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Abstract

Psychostimulants are used for the treatment of excessive daytime sleepiness in a wide range of sleep disorders as well as in attention deficit hyperactivity disorder or cognitive impairment in neuropsychiatric disorders. Here, we tested in mice the wake-promoting properties of NLS-4 and its effects on the following sleep as compared with those of modafinil and vehicle. C57BL/6J mice were intraperitoneally injected with vehicle, NLS-4 (64 mg/kg), or modafinil (150 mg/kg) at light onset. EEG and EMG were recorded continuously for 24 h after injections and vigilance states as well as EEG power densities were analyzed. NLS-4 at 64 mg/kg induced significantly longer wakefulness duration than modafinil at 150 mg/kg. Although no significant sleep rebound was observed after sleep onset for both treatments as compared with their vehicles, modafinil-treated mice showed significantly more NREM sleep when compared to NLS-4. Spectral analysis of the NREM EEG after NLS-4 treatment indicated an increased power density in delta activity (0.75–3.5 Hz) and a decreased power in theta frequency range (6.25–7.25 Hz), while there was no differences after modafinil treatment. Also, time course analysis of the delta activity showed a significant increase only during the first 2 time intervals of sleep after NLS-4 treatment, while delta power was increased during the first 9 time intervals after modafinil. Our results indicate that NLS-4 is a highly potent wake-promoting drug with no sign of hypersomnia rebound. As opposed to modafinil, recovery sleep after NLS-4 treatment is characterized by less NREM amount and delta activity, suggesting a lower need for recovery despite longer drug-induced wakefulness.
ORIGINAL RESEARCH
published: 15 August 2018
doi: 10.3389/fnins.2018.00519
Frontiers in Neuroscience | www.frontiersin.org 1August 2018 | Volume 12 | Article 519
Edited by:
Véronique Fabre,
INSERM U1130 Neurosciences Paris
Seine, France
Reviewed by:
Chloe Alexandre,
School of Medicine, Johns Hopkins
University, United States
Akihiro Yamanaka,
Nagoya University, Japan
*Correspondence:
Mehdi Tafti
mehdi.tafti@unil.ch
Specialty section:
This article was submitted to
Sleep and Circadian Rhythms,
a section of the journal
Frontiers in Neuroscience
Received: 19 April 2018
Accepted: 11 July 2018
Published: 15 August 2018
Citation:
Luca G, Bandarabadi M, Konofal E,
Lecendreux M, Ferrié L, Figadère B
and Tafti M (2018) Lauflumide (NLS-4)
Is a New Potent Wake-Promoting
Compound. Front. Neurosci. 12:519.
doi: 10.3389/fnins.2018.00519
Lauflumide (NLS-4) Is a New Potent
Wake-Promoting Compound
Gianina Luca 1,2 , Mojtaba Bandarabadi 3, Eric Konofal 4, Michel Lecendreux 4,5 ,
Laurent Ferrié 6, Bruno Figadère 6and Mehdi Tafti 1,3
*
1Faculty of Biology and Medicine, Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland, 2Centre
Neuchâtelois de Psychiatrie, Neuchâtel, Switzerland, 3Department of Physiology, Faculty of Biology and Medicine, University
of Lausanne, Lausanne, Switzerland, 4Pediatric Sleep Disorders Center, AP-HP, Robert Debre Hospital, Paris, France,
5AP-HP, Pediatric Sleep Center and National Reference Centre for Orphan Diseases, Narcolepsy, Idiopathic Hypersomnia
and Kleine-Levin Syndrome (CNR Narcolepsie-Hypersomnie), CHU Robert-Debre, Paris, France, 6BioCIS, Université
Paris-Sud, CNRS, Université Paris Saclay, Châtenay-Malabry, France
Psychostimulants are used for the treatment of excessive daytime sleepiness in a wide
range of sleep disorders as well as in attention deficit hyperactivity disorder or cognitive
impairment in neuropsychiatric disorders. Here, we tested in mice the wake-promoting
properties of NLS-4 and its effects on the following sleep as compared with those
of modafinil and vehicle. C57BL/6J mice were intraperitoneally injected with vehicle,
NLS-4 (64 mg/kg), or modafinil (150 mg/kg) at light onset. EEG and EMG were recorded
continuously for 24 h after injections and vigilance states as well as EEG power densities
were analyzed. NLS-4 at 64 mg/kg induced significantly longer wakefulness duration
than modafinil at 150 mg/kg. Although no significant sleep rebound was observed after
sleep onset for both treatments as compared with their vehicles, modafinil-treated mice
showed significantly more NREM sleep when compared to NLS-4. Spectral analysis of
the NREM EEG after NLS-4 treatment indicated an increased power density in delta
activity (0.75–3.5 Hz) and a decreased power in theta frequency range (6.25–7.25 Hz),
while there was no differences after modafinil treatment. Also, time course analysis of the
delta activity showed a significant increase only during the first 2 time intervals of sleep
after NLS-4 treatment, while delta power was increased during the first 9 time intervals
after modafinil. Our results indicate that NLS-4 is a highly potent wake-promoting drug
with no sign of hypersomnia rebound. As opposed to modafinil, recovery sleep after
NLS-4 treatment is characterized by less NREM amount and delta activity, suggesting a
lower need for recovery despite longer drug-induced wakefulness.
Keywords: stimulant, modafinil, rebound hypersomnia, EEG delta power, recovery sleep
INTRODUCTION
Excessive daytime sleepiness (EDS) is a major symptom of a wide range of sleep disorders. Clinical
management of EDS includes the use of psychostimulants such as modafinil and methylphenidate.
With increasing number of patients with EDS there is an increasing interest and need for wake-
promoting drugs with high efficacy and low side effects. Modafinil is the gold standard stimulant
for the treatment of EDS in narcolepsy and other hypersomnias (Mayer et al., 2015; Barateau
et al., 2016). The mechanism of action of modafinil is still unclear, but evidence indicates that it
Luca et al. NLS-4 Is a New Stimulant
differs from amphetamine in structure, neurochemical profile,
and behavioral effects (Minzenberg and Carter, 2008). Studies
suggest that although inhibition of dopamine (DA) reuptake
may be a primary mechanism underlying modafinil’s therapeutic
actions, non-DA-dependent actions may be playing a role in
its psychostimulant profile (Mereu et al., 2017). Moreover,
beside its wake-promoting properties, evidence to date suggests
that modafinil is well tolerated, safe, and lacking any of the
euphorigenic or reinforcing properties that can lead to addiction
(Ballon and Feifel, 2006). Pitolisant, a histamine H3 inverse
agonist is the newest and approved second-generation stimulant
with efficacy comparable to modafinil (Dauvilliers et al., 2013).
Another second-generation wake-promoting drug, JZP-110 is in
advanced clinical trials for the treatment of EDS in narcolepsy
and sleep apnea (Bogan et al., 2015; Ruoff et al., 2016). JZP-
110 is a potent dopaminergic-noradrenergic drug with efficacy
higher than modafinil (Hasan et al., 2009). Lauflumide [2-
((bis(4-fluorophenyl)methane)sulfinyl)acetamide] (NLS-4) was
conceptualized by the R&D of Laboratoire L. Lafon but has
never been developed. This bis (p-fluoro) ring-substituted
derivative of modafinil (Figure 1A) is an original potent
wake-promoting agent and produces anti-aggressive effects in
rats, which modafinil does not (Patent No.:US9,637.447B2).
Preliminary findings suggest that NLS-4 is a selective dopamine
reuptake inhibitor, blocking (83%) dopamine transporter (DAT),
higher than methylphenidate and without deleterious effects on
peripheral adrenergic systems involved in hypertension (Study
100014859 CEREP 20/03/14, unpublished data).
The aim of the present study was to evaluate the wake-
promoting properties of NLS-4 in mice, its effects on the
following sleep and to compare its pharmacological effects on
vigilance states with those of modafinil and vehicle.
MATERIALS AND METHODS
Animals
Adult male C57BL/6J mice (age: 10–11 weeks at the time of
surgery; weight: 22–26 g) were purchased from Charles River.
Mice were kept individually in polycarbonate cages (31 ×18 ×
18 cm) with food and water available ad libitum, and maintained
on a 12 h light–dark cycle (lights on at 09:00 h) at an ambient
temperature of 24.5–25.5C. The study protocols were approved
by the Veterinary Office of the Canton of Vaud, Switzerland.
Chemicals
NLS-4 was synthesized in 4 steps as described in Figure 1A.
We first determined the effective dose for NLS-4. C57BL/6J
mice (N=8) were individually housed as described above.
Activity was recorded under 12:12 h light-dark cycles. To
determine the NLS-4 dose that induces a robust wakefulness
period, locomotor activity was monitored and recorded using
infrared sensors. ClockLab software (Actimetrics) was used for
both data acquisition and analyses. Five NLS-4 doses were
administrated at light onset in ascending or descending order
every 24 h: vehicle, 32, 64 , 128, and 256 mg/kg. Sleep onset
was defined as the time elapsed between the time of injection
and the first inactivity episode (5 min of infrared uninterrupted
inactivity). Based on dose-response analysis (Figure 1B) the dose
of 64 mg/kg was chosen. For modafinil the dose of 150 mg/kg was
used based on our previous work (Hasan et al., 2009).
Another set of 8 mice per treatment was randomly assigned
to NLS-4 or modafinil treatment, receiving two intraperitoneal
injections in a random order (drug-vehicle or vehicle-drug)
at 24 h interval. After the 24 h baseline, mice received either
the drug or vehicle. NLS-4 was dissolved in 10% DMSO-saline
solution. As previously described (Hasan et al., 2009) modafinil
was not dissolved but suspended in the saline solution by
vortexing and injecting immediately each mouse. Drug solutions
were freshly prepared the same day before light onset. Control
solutions (vehicle) were 10% DMSO-saline solution for NLS-4
and saline for modafinil.
Sleep Recording and Analysis
EEG and EMG electrodes implantation was performed under
deep anesthesia as previously described (Hasan et al., 2009).
EEG/EMG signals were recorded using EMBLA hardware and
Somnologica-3 software (Flaga, Iceland). The animal’s behavior
was scored based on visual inspection of EEG and EMG signals
every 4 s as wakefulness, non-rapid eye movement (NREM), or
REM sleep.
The EEG spectral analysis was performed as described
previously (Vienne et al., 2010). Briefly, the EEG signal (frontal-
central) was subjected to a discrete Fourier transformation
yielding power spectra (range: 0.25–25 Hz; resolution: 0.25 Hz;
window function: hamming) for 4-s artifact-free epochs. Two
mice treated with NLS-4 (N=6) and one treated with modafinil
(N=7) were excluded from the analysis due to artifacts. Spectral
composition was generated using PRANA software. The EEG
delta power during NREM sleep was calculated by averaging
power density in the frequency bins from 0.75 to 4 Hz (Mang and
Franken, 2012). Values were normalized per mouse by expressing
them as a percentage of the mean delta power over NREM
sleep in the last 4 h of the baseline light period (when all mice
reach the lowest 24 h level of delta power). The time course of
EEG delta power in NREM sleep was calculated for the sleep
following drug administration. To adjust and compensate for
the different amount of NREM sleep across the light and dark
cycle, NREM amounts were subdivided into intervals (12 time
intervals during the light period and 6 for the dark period; see
Figure 4) with an equal number of contributing NREM epochs
for all intervals of the respective segment (e.g., the durations of
NREM sleep as reported in Table 1 are divided into 12 equal
segments during the light and 6 during the dark period: for NLS-4
light: 254/12 =21 min, dark: 174/6 =29 min on average for each
time interval).
Statistical Analysis
The amount of drug-induced wakefulness was analyzed by
paired t-test (drug vs. vehicle). To directly compare the
between drug difference in drug-induced wakefulness the
duration of vehicle-induced wakefulness was subtracted from
that of the drug for each mouse and the mean durations
were analyzed by t-test (Figure 1C). The hourly amounts of
NREM sleep after drug administration were analyzed separately
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Luca et al. NLS-4 Is a New Stimulant
FIGURE 1 | (A) NLS-4 was synthesized through a straightforward method involving first a Grignard addition of the desired 4-fluorophenylmagnesium bromide onto
4-fluorobenzaldehyde to provide p-fluorobenzydrol. Addition of thiourea in bromohydric medium, followed by treatment of the thiourea adduct with aqueous NaOH
and alkylation with 2-chloroacetamide afforded intermediate “A.” Finally, asymmetric oxidation of thioether “A” into (R)-sulfoxide by using Kagan method (Pitchen and
Kagan, 1984) led to expected NLS-4 compound in 23% overall yield in 4 steps (Cao et al., 2010). (B) Amount of spontaneous locomotor activity measured after
intraperitoneal administration of increasing doses of NLS-4 at light onset (N=8). (C) Duration of EEG recorded wakefulness after administration of 64 mg/kg of
NLS-4, 150 mg/kg of modafinil, or vehicle. Both drugs significantly increased the amount of wakefulness (paierd t-test, *P<0.05) but NLS-4-induced wake duration
was significantly higher than that of modafinil (t-test, *P<0.05). +indicates drug-vehicle value.
for each drug by a 2-way repeated measures ANOVA with
factor “treatment” (drug vs. vehicle) and “time” (time points
after drug injection). To directly compare the between drug
differences in NREM sleep distribution the amount of vehicle-
induced NREM sleep was subtracted from that of the drug
for each mouse and the mean hourly values were compared
by a 2-way ANOVA with factor “drug” (NLS-4 vs. vehicle)
and “time” (time points after drug injection). The power
densities during each vigilance states and the time course
of the slow wave activity during NREM sleep were analyzed
separately for each drug by a 2-way repeated measures ANOVA
with factor “treatment” (drug vs. vehicle) and “frequency”
(frequency bins in Hz) or “time” (time points after drug
injection), respectively. To directly compare the between drug
differences, values of drug condition were divided by those
of vehicle for each mouse and the mean power densities
were compared by a 2-way ANOVA with factor “drug” (NLS-
4 vs. vehicle) and “frequency” (frequency bins in Hz), or
“time” (time points after drug injection), respectively. All
statistical analyses were performed with GraphPad Prism
and all post-hoc tests were Sidak corrected for multiple
comparisons.
RESULTS
Vigilance States
Both NLS-4 (N=8) and modafinil (N=8) increased
the duration of drug-induced wakefulness compared with
vehicle (Figure 1C) (paired t-test between “drug” and “vehicle
condition, p<0.05, Table 1). Subtracting the vehicle-induced
from that of drug-induced wakefulness indicated that NLS-
4 administration resulted in an overall longer wakefulness
duration (151.18 ±15.33 min for NLS-4 and 109.67 ±16.59 min
for modafinil, p<0.05, t-test, Figure 1C). Neither NLS-4
nor modafinil induced hyper locomotor, stereotypic activity,
or abnormal behavior (by direct observation, infra-red and
video recording). The distribution of vigilance states after
sleep onset (defined as 3 consecutive epochs of NREM sleep
or 12 s) was affected in both groups. NREM sleep amount
for NLS-4 was significantly lower, and NLS-4-treated mice
had overall less NREM sleep as compared with modafinil-
treated group (Figure 2). The recovery of lost NREM sleep
(NREM accumulation minus vehicle) at the end of the light
period (12 h after drug administration) indicated a deficit
of 87.61 ±36.78 min for NLS-4 and of 45.04 ±19.96 min
for modafinil-treated mice.For modafinil-treated group the
recovery of lost NREM sleep further continued to the
dark period, leading into a significantly larger amount of
accumulated NREM sleep at the end of the 24 h recording
(Table 1).
For both NLS-4 and modafinil-treated groups, REM sleep
amount was decreased during the light and increased during
the dark recovery period, as compared to vehicle (Figure 2,
Table 1). The analysis of vigilance states bout duration and
number indicated no significant differences between drugs or
between drugs and vehicles.
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Luca et al. NLS-4 Is a New Stimulant
TABLE 1 | Distribution of vigilance states during the 24 h after drug administration.
NLS-4 (N=8) Vehicle (N=8) Modafinil (N=8) Vehicle (N=8) NLS-4 vs.
Modafinil
P
Sleep latency after
drug injection
208.18 ±12.99***a55.92 ±11.52 178.25 ±12.59***a56.18 ±9.82 <0.05b
NREM Light 254.41 ±21.16***c342.02 ±22.67 292.73 ±29.86***c337.76 ±23.06 <0.05d
Dark 174.86 ±49.90 158.50 ±37.10 206.81 ±32.70**c178.94 ±28.13 nsd
REM Light 40.67 ±6.94**c49.84 ±6.14 41.41 ±10.42**c45.74 ±11.23 <0.05d
Dark 21.88 ±10.12*c16.71 ±7.67 20.95 ±5.95***c14.29 ±7.85 nsd
Wake Light 223.30 ±37.57**c273.37 ±19.28 226.21 ±52.35**c285.73 ±25.42 nsd
Dark 523.25 ±58.66 544.79 ±44.03 490.26 ±35.98 525.83 ±34.54 nsd
NREM sleep loss Light 87.61 ±36.78 45.04 ±19.96 <0.05d
Dark 71.25 ±23.55 17.17 ±51.43 <0.05d
REM sleep loss Light 9.18 ±3.88 4.33 ±4.37 <0.05d
Dark 4.23 ±1.50 2.32 ±6.33 <0.01
All values are mean ±SD. *P<0.05, **P<0.01, *** P<0.001.
aPaired t-test.
bt-test.
c2-way repeated measures ANOVA.
d2-way ANOVA, ns: non-significant. NREM and REM sleep losses correspond to the differences of accumulated sleep between drugs and their respective vehicles at the end of the
light and dark period.
EEG Spectral Composition After the Drug
Administration
The EEG spectral composition did not differ at baseline or during
vehicle administration between the two drugs. We compared
NREM, REM and Wake relative power densities to evaluate the
differences between vehicle and drug (2-way repeated measures
ANOVA, factors “drug,” “bin (Hz),” and their interaction). Also,
the spectral composition was compared between the two drugs. A
similar analysis was also performed for absolute power densities.
NREM Sleep
NLS-4 induced an increase in 0.75–3.25 Hz frequency range, and
lower relative power in 6.25–7.25 Hz frequency range (Figure 3).
No significant differences in overall spectral composition were
identified for modafinil-treated mice. Analysis of absolute power
densities confirmed that only NLS-4 increased delta power.
Between drug comparisons did not reveal any significant drug or
interaction effect (Supplementary Figure 1).
REM Sleep and Wake
Only NLS-4 induced a decrease in relative theta power densities
during REM sleep (Figure 3). A similar decrease was also found
for the absolute power densities (Supplementary Figure 1).
NLS-4 induced a significant increase in the relative low
delta power during wakefulness while modafinil had no effect
(Figure 3). Similarly, NLS-4 treatment induced an increase in
absolute power in low delta frequencies during wakefulness,
while modafinil-treated mice showed lower absolute power at
8.25 Hz only (Supplementary Figure 1).
EEG Delta Power During NREM Sleep
Sleep following the drug-induced wakefulness showed a
significant increase in delta power. Delta power was increased
only for the first 2 time intervals for NLS-4-treated mice
(Figure 4), while modafinil treatment resulted in increased delta
power for the first 9 time points and time point 12. The overall
difference in NLS-4 treated mice was significantly lower than in
modafinil-treated ones (Figure 4).
Spectral Composition of Drug-Induced Wakefulness
The comparison between drug-induced and vehicle-induced
wakefulness showed only an increase in low delta power [2-
way repeated measures ANOVA, NLS-4: “treatment” p>0.1,
F(1, 5) =2.5, “bin” p<0.001, F(97, 485) =46.23, interaction
p<0.05, F(97, 485) =1.31, modafinil: “treatment” p>0.7,
F(1, 6) =0.07, “bin” p<0.001, F(97, 582) =39.25, interaction
p<0.01, F(97, 582) =1.46, multiple comparisons:p<0.05 for
0.75 Hz with drug>vehicle].
DISCUSSION
We compared vigilance states and spectral power densities
during and after administration of NLS-4 and modafinil in mice.
NLS-4 was found to be a highly potent wake-promoting drug
with less than half of the modafinil dose resulting in significantly
longer wakefulness. No significant changes in behavior (signs
of hyper locomotor activity) were found either under NLS-4 or
modafinil. Rebound hypersomnia (over compensation), typically
found with amphetamine or methyphenidate (Gruner et al.,
2009; Hasan et al., 2009), was not observed for either drugs.
Nevertheless, more sleep was found after wake-induced period by
modafinil as compared to NLS-4. Spectral analysis of wakefulness
during and sleep after drug-induced wakefulness revealed that
both drugs increased EEG power densities within the slow
frequencies (<4 Hz) but the increase by NLS-4 was significantly
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Luca et al. NLS-4 Is a New Stimulant
FIGURE 2 | Hourly distribution of vigilance states after NLS-4, modafinil, and vehicle administration (mean±SEM). After initial suppression of NREM sleep by both
drugs [2-way repeated measures ANOVA, NLS-4: “treatment” p<0.0001, F(1, 7) =73.25, “hour”, p<0.0001, F(23, 161) =17.21, interaction, p<0.0001,
F(23, 161)=4.16; modafinil: “treatment” p>0.38, F(1, 7) =0.89, “hour” p<0.0001, F(23, 161) =20.18; interaction, p<0.0001, F(23, 161) =5.10], the distribution
of NREM sleep during recovery is very similar to that after vehicle indicating the absence of sleep rebound (hypersomnia). Nevertheless, comparisons between the two
drugs indicated significantly less NREM sleep after NLS-4 administration as compared to modafinil [2-way ANOVA, drug effect: F(1, 14) =7.31, p<0.02]. REM sleep
is also suppressed during the first hours after drug injection while wakefulness is increased. Upward and downward triangles indicate significant increase or decrease,
respectively. Shaded areas indicate the dark period. +indicates drug/vehicle ratio.
lower than modafinil despite the fact that NLS-4 induced a
longer wakefulness amount. Although NLS-4 is a derivative of
modafinil, our results indicate that not only is it more potent than
modafinil at the doses tested but also wakefulness induced by
NLS-4 is compensated by less NREM sleep as well as delta power.
Drug Effects on Wakefulness Amount
Our dose-response study based on spontaneous locomotor
activity indicated a substantial increase in NLS-4-induced
wakefulness up to 64 mg/kg but no further increment at 128
and 256 mg/kg. We previously reported that modafinil increased
wakefulness in a linear manner between 100 and 300 mg/kg
(Hasan et al., 2009). The dose of 64 mg/kg was chosen for NLS-4
because this dose induced 4 h of wakefulness (Figures 1C,2)
similar to our previous report with modafinil at 150 mg/kg
(Hasan et al., 2009). Sleep recordings indicated a large increase in
wakefulness during the first 4 h after both NLS-4 and modafinil
administration as compared to vehicle and NLS-4 at 64 mg/kg
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Luca et al. NLS-4 Is a New Stimulant
FIGURE 3 | Relative spectral profiles of wake, NREM and REM sleep after drug-induced wakefulness (from sleep onset till the end of the 24 h recording). No changes
were observed between modafinil and vehicle while NLS-4 showed increased power densities in delta frequency range [2-way repeated measures ANOVA,
“treatment” p>0.65, F(1, 5) =0.22, “bin” p<0.0001, F(97, 485) =133.60, interaction p<0.0001, F(97, 485) =6.66]. Additionally, theta power density was
decreased during NREM and REM sleep under NLS-4 treatment [2-way repeated measures ANOVA, “treatment”, p>0.16, F(1, 5) =2.57, “bin” p<0.0001,
F(97, 485) =736.60, interaction p<0.0001, F(97, 485) =4.28; multiple comparisons: p <0.05 for: 6.5–7.75 Hz, with drug<vehicle]. Low delta power was increased
during wakefulness after NLS-4 treatment while no changes were observed after modafinil [2-way repeated measures ANOVA, NLS-4: “treatment” p>0.28,
F(1, 5) =1.45, “bin” p<0.0001, F(97, 485) =64.03, interaction p<0.01, F(97, 485) =1.55, multiple comparisons: p <0.05 for: 0.75–1.25 Hz, with drug>vehicle
and 4.25 Hz, with drug<vehicle]. Upward and downward triangles indicate significant increase or decrease in power, respectively.
FIGURE 4 | Time course of slow-wave (delta) activity (0.75–4 Hz) during NR EM sleep following drug-induced wakefulness. Delta power is increased during the first 2
time intervals of sleep after NLS-4 [2-way repeated measures ANOVA, “treatment” p>0.9, F(1, 5) =0.01, “hour” p<0.001, F(17, 85) =11.79, interaction p<0.001,
F(17, 85) =5.04] and during the first 9 time intervals after modafinil administration [2-way repeated measures ANOVA, “treatment” p<0.05, F(1, 6) =9.35, “hour” p<
0.001, F(17, 102) =17.88, interaction p<0.05, F(17, 102) =2.04]. Comparison between drugs indicates an overall increased spectral power after modafinil
administration [2-way ANOVA, “drug” p<0.05, F(1, 11) =5.23, “hour” p<0.001, F(17, 187) =4.39, interaction p=ns, F(17, 187) =0.93]. Upward and downward
triangles indicate significant increase or decrease in delta power, respectively. Shaded areas indicate the dark period.
induced significantly longer wakefulness duration as compared
to modafinil at 150 mg/kg. These results indicate that NLS-4 is
more potent wake-promoting drug than modafinil at the doses
tested.
Drug Effects on EEG During Induced
Wakefulness
One important aspect of any stimulant is the quality of the
induced wakefulness. Our direct observations (visually and by
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Luca et al. NLS-4 Is a New Stimulant
video) did not reveal any hyperactivity under NLS-4 or modafinil.
We next analyzed the EEG during drug-induced wakefulness.
As compared with vehicle, waking induced by NLS-4 as well
as modafinil showed a significant increase in low delta activity
only. This finding is consistent with the drug-induced long
wakefulness duration. Since no other significant changes were
observed, we conclude that both drugs produce similar and
normal wakefulness.
Drug Effects on Recovery Sleep
The effects of both NLS-4 and modafinil disappeared after 4 and
2 h and from this point on there were no significant differences
between the drug and the vehicle condition (except a slight
increase in NREM sleep at hour 19 under modafinil). This
indicates that none of these drugs induce rebound hypersomnia.
Rebound hypersomnia is a well-established side effect of the
classical stimulants such as amphetamine, methamphetamine,
and phentermine (Gruner et al., 2009; Hasan et al., 2009).
It was suggested that this side effect is due to increased
release of cathecholamines, especially dopamine, while dopamine
reuptake blockers do not present such an undesirable side effect
(Gruner et al., 2009). Nevertheless, cocaine, bupropion, and
methylphenidate (dopamine active transporter inhibitors) also
induce rebound hypersomnia, suggesting that other mechanisms
(such as pharmacokinetic) are involved (Gruner et al., 2009).
Other stimulants such as mazindol and JZP-110 are lacking the
rebound hypersomnia and must act as dopamine transporter
inhibitors (Gruner et al., 2009; Hasan et al., 2009). It was
also suggested that some stimulants such as cocaine produce
late hypersomnia (12–24 h after administration) (Dugovic et al.,
1992). NLS-4 not only did not induce late NREM sleep
rebound but even induced a decrease in the middle of
the dark period with a significant decrease in delta power
(18 h after drug administration), while modafinil induced a
significant increase in NREM sleep at hour 19 (7 h into
the dark period) as compared with vehicle. Comparison of
recovery sleep between the two drugs revealed significantly less
NREM sleep after NLS-4 administration (Figure 2), suggesting
that less NREM sleep is accumulated (or compensated)
during first hours of recovery after NLS-4 as compared to
modafinil.
Drug Effects on the Recovery Sleep EEG
Modafinil did not change any aspects of the waking EEG
spectral powers during the recovery period while NLS-4 induced
increased low delta and decreased high delta (Figure 3). Power
densities within the delta range were significantly increased
during recovery NREM sleep after NLS-4 while theta power
density was decreased. Modafinil did not induce any significant
changes. Overall, NLS-4 significantly increased power densities
when compared to vehicle, strongly suggesting that recovery
after NLS-4 occurred principally through an increase in sleep
intensity. Only NLS-4 induced decreased power densities in high
theta range (6.5–7.25 Hz) during REM sleep, as compared with
vehicle. The significance of the changes in the theta range during
both NREM and REM sleep remains unknown.
The time course analysis of the delta activity during NREM
sleep (an index of sleep homeostasis) indicated a significant
increase (during the first 2 time intervals of recovery sleep) after
NLS-4 and more after modafinil (first 9 time intervals of recovery
sleep). Interestingly, mice slept less during this period after NLS-
4 confirming that recovery after NLS-4-induced wakefulness
occurred with less NREM amount and less delta activity. Another
interesting observation is that although animals under NLS-4
stayed awake longer, delta activity was increased during a longer
period in modafinil treated animals after sleep onset, suggesting
that recovery occurred faster after NLS-4.
In summary, NLS-4 is a potent stimulant with different effects
than its parent compound modafinil (Rambert et al., 1986) and
most other stimulants in terms of potency and effects on sleep
rebound and the sleep EEG.
ETHICS STATEMENT
This study was carried out in accordance with the
recommendations of the Swiss Federal Food Safety and
Veterinary Office. The protocol was approved by the Veterinary
Office of the Vaud State, Lausanne.
AUTHOR CONTRIBUTIONS
MT, EK, and ML designed the study. GL conducted the
experiments. MT, GL, and MB analyzed the data. LF
and BF synthetized the NLS-4 compound. All authors
contributed to the draft and the final version of the
manuscript.
FUNDING
This work was supported by the University of Lausanne and
partly by an unrestricted research grant from NLS Pharma
(Switzerland).
ACKNOWLEDGMENTS
The authors thank Mr. Yann Emmenegger for technical
assistance.
SUPPLEMENTARY MATERIAL
The Supplementary Material for this article can be found
online at: https://www.frontiersin.org/articles/10.3389/fnins.
2018.00519/full#supplementary-material
Supplementary Figure 1 | Absolute spectral profiles of wake, NREM and REM
sleep after drug-induced wakefulness. NLS-4 showed increased power densities
in delta frequency range during wakefulness and NREM sleep and decreased
power densities in theta frequency range [NLS-4: 2-way repeated measures
ANOVA, “treatment” p>0.11; F(1, 5) =3.66, “bin” p<0.0001, F(97, 485) =
46.43, interaction p<0.0001, F(97, 485) =5.80; multiple comparisons: p <0.05
for: 0.75–4.00 Hz, with drug>vehicle]. Low delta power was increased during
wakefulness after NLS-4 treatment [2-way repeated measures ANOVA,
“treatment” p>0.5; F(1,5) =0.51, “bin” p<0.0001, F(97, 485) =24.20,
interaction p<0.001, F(97, 485) =1.59; multiple comparisons:p<0.05 for:
0.75–1.25 Hz, with drug>vehicle] while modafinil induced lower absolute power at
8.25 Hz [2-way repeated measures ANOVA, “treatment” p>0.39, F(1, 6) =0.84,
“bin” p<0.0001, F(97, 582) =20.90, interaction p<0.01, F(97, 582) =1.43;
multiple comparisons:p<0.05 for 8.25 Hz, with drug>vehicle]. Upward and
downward triangles indicate significant increase or decrease in power, respectively.
Frontiers in Neuroscience | www.frontiersin.org 7August 2018 | Volume 12 | Article 519
Luca et al. NLS-4 Is a New Stimulant
REFERENCES
Ballon, J. S., and Feifel, D. (2006). A systematic review of modafinil: potential
clinical uses and mechanisms of action. J. Clin. Psychiatry 67, 554–566.
doi: 10.4088/JCP.v67n0406
Barateau, L., Lopez, R., and Dauvilliers, Y. (2016). Management of
narcolepsy. Curr. Treat. Options Neurol. 18:43. doi: 10.1007/s11940-016-
0429-y
Bogan, R. K., Feldman, N., Emsellem, H. A., Rosenberg, R., Lu, Y., Bream, G.,
et al. (2015). Effect of oral JZP-110 (ADX-N05) treatment on wakefulness
and sleepiness in adults with narcolepsy. Sleep Med. 16, 1102–1108.
doi: 10.1016/j.sleep.2015.05.013
Cao, J., Prisinzano, T. E., Okunola, O. M., Kopajtic, T., Shook, M., Katz, J. L.,
et al. (2010). Structure-activity relationships at the monoamine transporters
for a novel series of modafinil (2-[(diphenylmethyl)sulfinyl]acetamide)
Analogues. ACS Med. Chem. Lett. 2, 48–52. doi: 10.1021/
ml1002025
Dauvilliers, Y., Bassetti, C., Lammers, G. J., Arnulf, I., Mayer, G., Rodenbeck,
A., et al. (2013). Pitolisant versus placebo or modafinil in patients with
narcolepsy: a double-blind, randomised trial. Lancet Neurol. 12, 1068–1075.
doi: 10.1016/S1474-4422(13)70225-4
Dugovic, C., Meert, T. F., Ashton, D., and Clincke, G. H. (1992). Effects
of ritanserin and chlordiazepoxide on sleep-wakefulness alterations in rats
following chronic cocaine treatment. Psychopharmacology 108, 263–270.
doi: 10.1007/BF02245110
Gruner, J. A., Marcy, V. R., Lin, Y. G., Bozyczko-Coyne, D., Marino, M.
J., and Gasior, M. (2009). The roles of dopamine transport inhibition
and dopamine release facilitation in wake enhancement and rebound
hypersomnolence induced by dopaminergic agents. Sleep 32, 1425–1438.
doi: 10.1093/sleep/32.11.1425
Hasan, S., Pradervand, S., Ahnaou, A., Drinkenburg, W., Tafti, M., and
Franken, P. (2009). How to keep the brain awake? the complex molecular
pharmacogenetics of wake promotion. Neuropsychopharmacology 34,
1625–1640. doi: 10.1038/npp.2009.3
Mang, G. M., and Franken, P. (2012). Sleep and EEG phenotyping in
mice. Curr. Protoc. Mouse Biol. 2, 55–74. doi: 10.1002/9780470942390.
mo110126
Mayer, G., Benes, H., Young, P., Bitterlich, M., and Rodenbeck, A. (2015).
Modafinil in the treatment of idiopathic hypersomnia without long sleep time-a
randomized, double-blind, placebo-controlled study. J. Sleep Res. 24, 74–81.
doi: 10.1111/jsr.12201
Mereu, M., Chun, L. E., Prisinzano, T. E., Newman, A. H., Katz, J. L., and Tanda,
G. (2017). The unique psychostimulant profile of (±)-modafinil: investigation
of behavioral and neurochemical effects in mice. Eur. J. Neurosci. 45, 167–174.
doi: 10.1111/ejn.13376
Minzenberg, M. J., and Carter, C. S. (2008). Modafinil: a review of neurochemical
actions and effects on cognition. Neuropsychopharmacology 33, 1477–1502.
doi: 10.1038/sj.npp.1301534
Pitchen, P., and Kagan, H (1984). An efficient asymmetric oxidation
of sulfides to sulfoxides. Tetrahedron Lett. 25, 1049–1052.
doi: 10.1016/S0040-4039(01)80097-6
Rambert, F. A., Pessonnier, J., De Sereville, J. E., Pointeau, A. M., and Duteil,
J. (1986). A unique psychopharmacologic profile of adrafinil in mice. J.
Pharmacol. 17, 37–52.
Ruoff, C., Swick, T. J., Doekel, R., Emsellem, H. A., Feldman, N. T., Rosenberg,
R., et al. (2016). Effect of oral JZP-110 (ADX-N05) on wakefulness and
sleepiness in adults with narcolepsy: a Phase 2b Study. Sleep 39, 1379–1387.
doi: 10.5665/sleep.5968
Vienne, J., Bettler, B., Franken, P., and Tafti, M. (2010). Differential effects
of GABAB receptor subtypes, {gamma}-hydroxybutyric acid, and baclofen
on EEG activity and sleep regulation. J. Neurosci. 30, 14194–14204.
doi: 10.1523/JNEUROSCI.3145-10.2010
Conflict of Interest Statement: MT, EK, ML and BF received compensation from
private or publicly owned organizations for serving as an advisory or scientific
board member or as an invited speaker.
The remaining authors declare that the research was conducted in the absence of
any commercial or financial relationships that could be construed as a potential
conflict of interest.
Copyright © 2018 Luca, Bandarabadi, Konofal, Lecendreux, Ferrié, Figadère and
Tafti. This is an open-access article distributed under the terms of the Creative
Commons Attribution License (CC BY). The use, distribution or reproduction in
other forums is permitted, provided the original author(s) and the copyright owner(s)
are credited and that the original publication in this journal is cited, in accordance
with accepted academic practice. No use, distribution or reproduction is permitted
which does not comply with these terms.
Frontiers in Neuroscience | www.frontiersin.org 8August 2018 | Volume 12 | Article 519

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