Article

Tyrosine hydroxylase- and dopamine transporter-immunoreactive axons in the primate cerebellum - Evidence for a lobular- and laminar-specific dopamine innervation

Departments of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA.
Neuropsychopharmacology (Impact Factor: 7.83). 06/2000; 22(5):466-72. DOI: 10.1016/S0893-133X(99)00139-6
Source: PubMed

ABSTRACT The cerebellum seems to play a critical role in many motor and cognitive functions, including those that are disturbed in schizophrenia. Although dopamine is known to influence the motor or cognitive functions mediated by other brain regions and to play a role in the pathophysiology of schizophrenia, the cerebellum has not been thought to be a target of dopamine-containing axons. However, given recent reports of dopamine receptors in the cerebellum, we sought to determine whether axons immunoreactive for the proteins involved in dopamine synthesis and reuptake are present in the cerebellum of macaque monkeys. We found that axons immunoreactive for the dopamine membrane transporter, a specific marker of dopamine axons, were present in high density, but only in certain lobules of the cerebellar vermis. In addition, these axons were found principally in the granule cell layer, where they densely arborized immediately subjacent to the Purkinje cells. Similarly, axons labeled for tyrosine hydroxylase, the rate-limiting enzyme in catecholamine biosynthesis, were also present in high density in the granule cell layer of the same lobules of the vermis. In contrast, axons immunoreactive for dopamine beta-hydroxylase, a marker of noradrenergic axons, exhibited a different and more widespread pattern of innervation. These findings are consistent with a dopamine innervation of the primate cerebellum that is both lobular- and laminar-specific, and they suggest that dopamine may play a role in certain cerebellar functions.

0 Followers
 · 
51 Views
  • Source
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The stimulant drug methylphenidate (MPH) and the non-stimulant drug atomoxetine (ATX) are both widely used for the treatment of attention deficit/hyperactivity disorder (ADHD), but their differential effects on human brain function are poorly understood. PET and blood oxygen level dependent (BOLD) fMRI have been used to study the effects of MPH and BOLD fMRI is beginning to be used to delineate the effects of MPH and ATX in the context of cognitive tasks. The BOLD signal is a proxy for neuronal activity and is dependent on three physiological parameters: regional cerebral blood flow (rCBF), cerebral metabolic rate of oxygen and cerebral blood volume. To identify areas sensitive to MPH and ATX and assist interpretation of BOLD studies in healthy volunteers and ADHD patients, it is therefore of interest to characterize the effects of these drugs on rCBF. In this study, we used arterial spin labeling (ASL) MRI to measure rCBF non-invasively in healthy volunteers after administration of MPH, ATX or placebo. We employed multi-class pattern recognition (PR) to discriminate the neuronal effects of the drugs, which accurately discriminated all drug conditions from one another and provided activity patterns that precisely localized discriminating brain regions. We showed common and differential effects in cortical and subcortical brain regions. The clearest differential effects were observed in four regions: (i) in the caudate body where MPH but not ATX increased rCBF, (ii) in the midbrain/substantia nigra and (iii) thalamus where MPH increased and ATX decreased rCBF plus (iv) a large region of cerebellar cortex where ATX increased rCBF relative to MPH. Our results demonstrate that combining ASL and PR yields a sensitive method for detecting the effects of these drugs and provides insights into the regional distribution of brain networks potentially modulated by these compounds.
    NeuroImage 01/2012; 60(2):1015-24. DOI:10.1016/j.neuroimage.2012.01.058 · 6.13 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The cerebellum is generally considered a neural structure specialized in motor control and recent imaging data suggest its role in sexual behavior. Herein, we analyzed the pattern of Fos immunoreactivity (Fos-IR) in the cerebellum of female rats allowed to pace copulation as a model of sexual reward in rodents. Ovariectomized, hormone-primed, sexually naïve females formed three groups: Pacing, Nonpacing and Control. Pacing occurred in arenas bisected by a middle divider that allowed only females to control sexual interaction with stud males. For nonpaced copulation the divider was removed, and control females were allowed to pace in chambers without a male. Fos-IR was analyzed in granule and Purkinje layers of the 10 cerebellar lobules, and in the fastigial deep nucleus (FDN). Results indicated that Pacing females expressed more Fos-IR in the granule layer compared to Nonpacing and Controls, and more Fos-IR in Purkinje compared to Nonpacing. No differences were observed in FDN. Such response cannot be explained with motor activity because Pacing females moved less in general. We discuss the role of the cerebellum and its connections in the sexual reward induced by pacing.
    Physiology & Behavior 11/2010; 102(2):143-8. DOI:10.1016/j.physbeh.2010.11.004 · 3.03 Impact Factor

Preview

Download
0 Downloads
Available from