PHYSIOLOGICAL RESEARCH • ISSN 0862-8408 (print) • ISSN 1802-9973 (online)
© 2008 Institute of Physiology v.v.i., Academy of Sciences of the Czech Republic, Prague, Czech Republic
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Physiol. Res. 57 (Suppl. 3): S161-S165, 2008
Novel Behavioral Tasks for Studying Spatial Cognition in Rats
D. KLEMENT, K. BLAHNA, T. NEKOVÁŘOVÁ
Institute of Physiology, Academy of Sciences of the Czech Republic, v.v.i , Prague, Czech Republic
Received February 15, 2008
Accepted April 16, 2008
On-line May 13, 2008
Spatial tasks in rodents are commonly used to study general
mechanisms of cognition. We review two groups of novel spatial
tasks for rodents and discuss how they can extend our
understanding of mechanisms of spatial cognition. The first group
represents spatial tasks in which the subject does not locomote.
Locomotion influences neural activity in brain structures
important for spatial cognition. The tasks belonging to the first
group make it possible to study cognitive processes without the
interfering impact of locomotion. The second group represents
tasks in which the subject approaches or avoids a moving object.
Despite this topic is intensively studied in various animal species,
little attention has been paid to it in rodents. Both groups of the
tasks are powerful tools for addressing novel questions about
Spatial cognition • Rats • Moving objects • Behavioral tasks
D. Klement, Institute of Physiology, Academy of Sciences of the
Czech Republic, Vídeňská 1083, 142 20 Prague 4, Czech
Republic. Fax: +420-241
Cognition and its neural substrate are intensively
studied in many laboratories. Novel behavioral tasks with
well characterized cognitive demands are necessary for
further progress. Once a novel task is introduced, lesion,
pharmacological or electrophysiological studies can be
used to study whether and how certain brain areas are
involved in the underlying cognitive processes. In rodents
the research of learning and memory is focused on spatial
062 488. E-mail:
cognition. Here we present two types of novel spatial
tasks for rats: 1) tasks in which spatial cognition is tested
in non-locomoting animals and 2) tasks in which the
subjects navigate to or avoid a moving object. We discuss
how these tasks contributed or can contribute to the
research of spatial cognition.
Non-locomotor spatial tasks
Our knowledge of spatial cognition in rats is
mainly based on observation of locomotion. Through the
locomotion we study whether the subject is able to use
available sensory stimuli for navigation or whether it
remembers the location of a goal or of visited places.
Nevertheless, some questions
cognition are difficult to address by means of locomotor
tasks. Below we show two examples: the importance of
hippocampus for the ability to recognize places and the
relationship between hippocampal theta rhythm and
spatial cognition. To answer these and other questions it
is important to use spatial tasks in which the locomotion
is absent or at least minimized. Such tasks have used non-
spatial operant behavior controlled by spatial stimuli
(Klement and Bureš 2000, Pašťálková et al. 2003,
Kelemen et al. 2005, Nekovářová and Klement 2006,
Klement et al. 2008). Typically an animal is trained to
press a lever for reward but its responses are reinforced
only when they occur in the presence of a to-be-
recognized spatial stimulus. Preferential responding in the
presence of this stimulus indicates that the animal
Spatial tasks exploiting non-spatial operant
behavior have been used to study the ability to recognize
places (Klement and Bureš 2000, Pašťálková et al. 2003)
S162 Klement et al.
and the role of hippocampus in this ability (Klement et al.
2005). Hippocampus is necessary for navigation toward a
place which can be found only according to its spatial
relationship to distal landmarks (Morris et al. 1982).
During such navigation the subject has to determine
where to go in order to reach the place and, after it
reaches the desired position, to recognize it. For example,
rats easily learn to navigate toward a platform hidden
under the water surface using distal cues present around
the pool. If the platform is removed then they start to
search for it in the location, where it was in the previous
trials. The switch in behavior from goal directed
navigation to random search indicates that the animals
have recognized the place.
Researchers were interested whether the ability
to recognize places depends on hippocampus. This
question was addressed indirectly using spatial tasks in
which rats should actively move to the location
recognized as the goal place (Whishaw et al. 1995,
Whishaw and Jarrard, 1996, Dudchenko et al. 2000,
Pouzet et al. 2002, Hollup et al. 2001). These
experiments provided contradictory results about the role
of the hippocampus for place recognition. To help to
resolve this question Klement and Bureš (2000) used
non-spatial operant behavior controlled by spatial stimuli.
They tested place recognition without asking the animal
to actively move to the to-be-recognized place. Thus they
isolated the place recognition process from the recall of
the target position and from the navigation toward it.
Food deprived rats were placed in the box located on the
edge of a rotating arena and passively transported along a
circular trajectory. They could press a lever all the time
but their responses were rewarded by delivering a food
pellet only if they occurred within a limited region in the
experimental room. Accumulation of responses inside
and in the vicinity of the region indicated that the rats
were recognizing the region. Subsequent study showed
that this task is hippocampal dependent (Klement et al.
2005). The result supported the view that hippocampus is
necessary for recognizing places.
Several experiments demonstrated that theta
rhythm is present in hippocampus when the animal
moves across an environment or prepares for the
movement (Vanderwolf 1969, Ranck 1973). Theta
rhythm also organizes firing of hippocampal pyramidal
cells (O’Keefe and Recce 1993) and it is involved in
synaptic plasticity (Orr et al. 2001), phenomena thought
to be associated with cognition. However, it was unclear
whether theta rhythm reflects only locomotion or whether
it is also triggered by cognitive processes taking place in
hippocampus. To test this hypothesis it was necessary to
use a hippocampal dependent task in which rats do not
move. Kelemen et al. (2005) modified the place
recognition task described by Klement and Bureš (2000).
Rats were trained to hold their head motionless in a
drinking device while they were passively transported
along a circular trajectory. Licking was rewarded either in
the to-be-recognized region or randomly. The frequency
and the amplitude of theta rhythm were lower during the
passive transport compared to the active locomotion.
Nevertheless, there was no difference between theta
rhythm during the hippocampal dependent place
recognition task and during the random licking. Thus the
result supported the hypothesis that theta rhythm
primarily reflects locomotion.
Spatial cognition can be studied also in rats
which do not change their location in an experimental
room at all (Pašťálková et al. 2003, Nekovářová and
Klement 2006, Klement et al. 2008). Such experiments
allow to study spatial cognition and neuronal activity
reflecting the cognitive task in the absence of inertial
stimuli which are inevitably present during active
movement as well as during passive transport. Inertial
stimuli influence hippocampal theta rhythm (Gavrilov et
al. 1996), activity of place cells (Terrazas et al. 2005) and
head-direction cells (Blair and Sharp 1996). Pašťálková
et al. (2003) used an operant chamber with a window
through which the subject could observe a rotating scene.
The rats were trained to recognize a particular
displacement of the scene. The performance was equal to
the performance observed in the same rats when they
were passively transported around a stationary scene. In
the following studies (Nekovářová and Klement 2006,
Klement et al. 2008) rats were trained to press a lever
when a light cursor moving across a computer screen was
at the to-be-recognized place. These tasks make it
possible to study representation of position and velocity
of a moving object in the rat’s brain.
It has been demonstrated
preferentially explore objects which changed their
location between two consecutive sessions in comparison
with objects remaining on the same place (Ennaceur et al.
1997). This preference is hippocampal dependent
(Mumby 2002). O’Keefe and Nadel (1978) recorded
hippocampal neurons that fired extensively when the
animal did not find an object on a place where it was
present in the previous sessions. Rivard et al. (2004)
described hippocampal neurons with activity dependent
Novel Behavioral Tasks for Studying Spatial Cognition S163
on the presence of a particular object. The data indicate
that animals chart stationary objects into their
representation of an environment. However, moving
objects cannot be simply charted into a spatial
representation of the environment as they are not bound
to any location. It remains an unsolved question whether
there exist neurons representing position of these moving
objects and whether they are located in hippocampus.
Spatial task in which subjects are forced to observe a
moving object can help to answer this question. The
operant conditioning tasks presented in Nekovářová and
Klement (2006) and Klement et al. (2008) are suitable for
Spatial tasks in which the subject responds to
a moving object
The second group of behavioral tasks concerns
freely moving animal and its relation to objects moving
in the environment.
In their natural habitats animals react to moving
objects, e.g. to members of the same social group, mates,
preys or predators. In order to reach or to avoid them the
subject has to pay attention to them and quickly respond
to their movements. Strategies evolved for catching a
moving object was studied in different species (insect:
Collet and Land 1978, Rossel 1980, fish: Rossel et al.
2002, Wohl and Schuster 2006, humans: McBeath et al.
1995). However there is a lack of corresponding tasks for
rodents. Recently, novel tasks for rodents have been
introduced. The animals were trained either to avoid a
moving object (Pašťálková and Bureš 2001, Svoboda et
al. 2005, Blahna et al. 2007) or to approach it (Klement
and Blahna 2007).
Pašťálková and Bureš (2001), see also Fenton
and Bureš (2003), developed a behavioral task in which
one rat (prey) should avoid another rat (predator). Both
rats were placed on a circular arena. If the distance
between the predator and the prey was shorter than a
preset critical distance then the prey received an aversive
stimulus. Thus the prey should continuously monitor the
distance to the predator and to increase it when it became
necessary. Two factors made this task difficult: limited
space of the arena and the tendency of the predator to
make a social contact with the prey. To avoid these
constraints Svoboda et al. (2005) replaced the predator rat
by a mobile robot. The robot did not chase the rat and
moved slower than the predator rat in the previous
experiment. Rats increased the average distance to the
robot as the result of training and thus decreased the
number of received aversive stimuli. The increase
distance can be partly explained by the increased time the
rats spent at the arena wall (Telenský et al. 2006).
Inactivation of the hippocampus by tetrodotoxin impaired
rat’s performance without changing the thigmotactic
behavior and thus making it possible to interpret the
result as a cognitive deficit (Svoboda et al. 2006). Since
hippocampal rats are able to estimate distance from a
single visible cue (Pearce et al. 1998), the result suggests
that the observed impairment affected the ability to
initiate an escape reaction at the right moment rather than
the perception of distance. The avoidance task become
much more difficult when rats were trained to keep safe
distance from an object moving outside of the arena.
Only minority of the animals learned the task and their
asymptotic performance varied substantially between
consecutive sessions (Blahna et al. 2007).
In all the above tasks the animals avoided
moving objects on a dry arena. In contrast, Klement and
Blahna (2007) designed a task in which rats should
navigate to a platform moving along the wall in a circular
water pool. The platform did not change its speed within
the trials to makes it possible to predict its movement.
Since the rats were not allowed to wait for the target at
the wall they were forced to navigate toward the platform
across the pool. When the platform moved slower than
the rats, the animals most frequently swam directly
toward the platform. When the platform moved faster
than the rats, they swam at a point in front of the platform
generating relatively straight trajectories toward the place
of collision. Further experiments revealing the role of
various brain structures such as hippocampus and
prefrontal cortex in this task have to be carried on.
We presented two groups of novel behavioral
tasks. The tasks in the first group are operant
conditioning tasks. Their advantage is minimization or
even elimination of locomotion in spatial tasks. It allows
to study the role and the activity of different brain
structures in non-locomoting animals while they process
spatial information. The operant conditioning in spatial
research allows applying sensory stimuli with high
flexibility, particularly if they are displayed on a
computer screen. The computer screen makes it possible
to use almost countless number of different stimuli and
their combinations as well as to precisely control latency
S164 Klement et al.
and duration of stimuli presentation. In addition such
behavioral tasks can be easily modified and they are
suitable for comparing cognitive functions and their
neuronal substrate in various animal species including
humans. It is possible to design several versions of the
task presented in Nekovářová and Klement (2006) in
which all the experimental parameters such as timing,
behavioral response, motivation are identical except the
stimuli presented on the screen. In the same apparatus
rats can be trained to recognize various patterns,
configurations of stimuli or places. This phenomena is
illustrated by increasing number of novel behavioral tasks
using computer screen for presenting stimuli (Bussey et
al. 2001, Keller et al. 2000, Nekovářová and Bureš 2006,
Nekovářová et al. 2006, Prusky et al. 2004, Sahgal and
BLAHNA K, OSECKÁ B, KLEMENT D: Representation of moving object in different character of environment. In:
Neural Plasticity (39th Annual European Brain and Behaviour Society Abstracts), A TREVES, PP
BATTAGLINI, L CHELAZZI, M DIAMOND, G VALLORTIGARA (eds), Hindawi Publishing Corporation,
Trieste, 2007, pp 40-41.
BLAIR HT, SHARP PR: Visual and vestibular influences on head-direction cells in the anterior thalamus of the rat.
Behav Neurosci 4: 643-660, 1996.
COLLET TS, LAND MF: How hoverflies compute interception courses. J Comp Physiol 125: 191-204, 1978.
DUDCHENKO PA, WOOD ER, EICHENBAUM H: Neurotoxic hippocampal lesions have no effect on odor span and
little effect on odor recognition memory but produce significant impairments on spatial span, recognition, and
alternation. J Neurosci 20: 2964-2977, 2000.
ENNACEUR A, NEAVE N, AGGLETON JP: Spontaneous object recognition and object location memory in rats, the
effects of lesions in the cingulate cortices, the medial prefrontal cortex, the cingulum bundle and the fornix,
Experimental Brain Research 113: 509-519, 1997.
FENTON AA, BUREŠ J: Navigation in the moving world. In: The Neurobiology of Spatial Behaviour. KJ JEFFERY
(ed), Oxford University Press, Oxford, 2003, pp 240-258.
GAVRILOV VV, WIENER SI, BERTHOZ A: Whole-body rotations enhance hippocampal theta rhythmic slow activity
in awake rats passively transported on a mobile robot. Ann N Y Acad Sci 781: 385-98, 1996.
HOLLUP SA, KJELSTRUP KG, HOFF J, MOSER MB, MOSER EI: Impaired recognition of the goal location during
spatial navigation in rats with hippocampal lesions. J Neurosci 21: 4505-4513, 2001.
KELEMEN E, MORON I, FENTON AA: Is the hippocampal theta rhythm related to cognition in a non-locomotor
place recognition task? Hippocampus 15: 472-479, 2005.
KLEMENT D, BLAHNA K: Rat navigation to a visible moving goal in Morris water maze. In: 39th Annual European
Brain and Behaviour Society Abstracts. A TREVES, PP BATTAGLINI, L CHELAZZI, M DIAMOND,
G VALLORTIGARA (eds), Neural Plasticity, 2007, p 40.
KLEMENT D, BUREŠ J: Place recognition monitored by location driven operant responding during passive transport
of the rat over a circular trajectory. Proc Natl Acad Sci USA 97: 2946-2951, 2000.
KLEMENT D, PAŠŤÁLKOVÁ E, FENTON AA: Tetrodotoxin infusions into the dorsal hippocampus block non-
locomotor place recognition. Hippocampus 15: 460-471, 2005.
MCBEATH MK, SHAFFER DM, KAISER MK: How baseball outfielders determine where to run to catch fly balls.
Science 268: 569-573, 1995.
The tasks in the second group address the
cognitive and neural processes involved during
navigation toward or away from moving objects. Despite
this topic is intensively studied in various animal species,
little attention has been paid to it in rodents. The novel
behavioral tasks presented above will hopefully initiate
this research in rodents.
Conflict of Interest
There is no conflict of interest.
The research was supported by grants AV0Z50110509
and Center for Neuroscience LC554.
Novel Behavioral Tasks for Studying Spatial Cognition S165
MORRIS RG, GARRUD P, RAWLINS JN, O'KEEFE J: Place navigation impaired in rats with hippocampal lesions.
Nature 297: 681-683, 1982.
MUMBY DG, GASKIN S, GLENN MJ, SCHRAMEK TE, LEHMANN H: Hippocampal damage and exploratory
preferences in rats: memory for objects, places and contexts. Learn Mem 9: 49-57, 2002.
NEKOVÁŘOVÁ T, KLEMENT D: Rat’s operant behavior can be controlled by the configuration of objects in an
animated scene displayed on a computer screen. Physiol Res 55: 105-113, 2006.
NEKOVÁŘOVÁ T, BUREŠ J: Spatial decisions in rats based on the geometry of computer-generated patterns.
Neurosci Letters 394: 211-215, 2006.
NEKOVÁŘOVÁ T, NEDVÍDEK J, BUREŠ J: Spatial choices of rats based on abstract visual information: pattern- or
configuration-discrimination? Behav Brain Res 172: 264-271, 2006.
O'KEEFE J, RECCE ML: Phase relationship between hippocampal place units and the EEG theta rhythm.
Hippocampus 3: 317-330; 1993.
O´KEEFE J, NADEL L: The Hippocampus as a Cognitive Map. Clarendom Press, Oxford, 1978.
ORR G, RAO G, HOUSTON FP, MCNAUGHTON BL, BARNES CA: Hippocampal synaptic plasticity is modulated
by theta rhythm in the fascia dentate of adult and aged freely behaving rats. Hippocampus 6: 647-654, 2001.
PAŠŤÁLKOVÁ E, BUREŠ J: How do animals navigate to avoid each other? Abstracts of the Fourth Conference of the
Czech Neuroscience Society, Prague, 2001, p 104.
PAŠŤÁLKOVÁ E, KELEMEN E, BUREŠ J: Operant behavior can be triggered by the position of the rat relative to
objects rotating on an inaccessible platform. Proc Natl Acad Sci USA 100: 2094-2099, 2003.
POUZET B, ZHANG WN, FELDON J, RAWLINS JN: Hippocampal lesioned rats are able to learn a spatial position
using non-spatial strategies. Behav Brain Res 133: 279-291, 2002.
PRUSKY GT, DOUGLAS RM, NELSON L, SHABANPOOR A, SUTHERLAND RJ: Visual memory task for rats
reveals an essential role for hippocampus and perirhinal cortex. Proc Natl Acad Sci USA 101: 5064-5068,
RANCK JB Jr.: Studies on single neurons in dorsal hippocampal formation and septum in unrestrained rats. I.
Behavioral correlates and firing repertoires. Exp Neurol 41: 461-531, 1973.
RIVARD B, LI Y, LENCK-SANTINY PP, POUCET B, MULLER U: Representation of objects in space by two classes
of hippocampal pyramidal cells. J Gen Physiol 124: 3-6, 2004.
ROSSEL S, CORLIA J, SCHUSTER S: Predicting three-dimensional target motion: How archer fish determine where
to catch their dislodged prey J Exp Biol 205: 3321-3326, 2002.
SAHGAL A, STECKLER T: Touch windows and operant behaviour in rats. J Neurosci Methods 55: 59-64, 1994.
SVOBODA J, TELENSKÝ P, BLAHNA K, PAŠŤÁLKOVÁ E, BUREŠ J: Introducing of moving object into
behavioral spatial tasks: moving object avoidance in rats. Homeostasis 43: 4, 2005.
SVOBODA J, TELENSKÝ P, BLAHNA K, BUREŠ J: Functional inactivation of dorsal hipocampus impairs spatial
avoidance of moving object in rats. Abstracts of the Fifth Forum of European Neuroscience, Vienna, 2006,
TELENSKÝ P, JIROUTEK P, SVOBODA J, BLAHNA K, BUREŠ J: Biologická evoluce versus evoluční systémy:
porovnání učení potkana a robota v dynamických prostorových úlohách srovnatelného typu. In: Kognice a
umělý život VI. J KELEMEN, V KVASNIČKA (eds): Ediční středisko FPF SU, Opava, 2006, pp 373-391.
TERRAZAS A, KRAUSE M, LIPA P, GOTHARD KM, BARNES CA, MCNAUGHTON BL: Self-motion and the
hippocampal spatial metric. J Neurosci 25, 8085-8096, 2005.
VANDERWOLF CH: Hippocampal electrical activity and voluntary movement of the rat. Electroencephalogr Clin
Neurophysiol 26: 407-418, 1969.
WHISHAW IQ, CASSESL JC, JARRAD LE: Rats with fimbria-fornix lesions display a place response in a swimming
pool: a dissociation between getting there and knowing where. J Neurosci 15: 5779-5788, 1995.
WHISHAW IQ, JARRAD LE: Evidence for extrahippocampal involvement in place learning and hippocampal
involvement in path integration. Hippocampus 6: 513-524, 1996.
WOHL S, SCHUSTER S: Hunting archer fish match their take-off speed to distance from the future point of catch
J Exp Biol 209: 141-151, 2006.