Neuroanatomical Basis (neuroanatomical + basis)

Distribution by Scientific Domains


Selected Abstracts


Neuroanatomical basis for therapeutic applications of cannabinoid receptor 1 antagonists

DRUG DEVELOPMENT RESEARCH, Issue 8 2009
Brian F. Thomas
Abstract The CB1 receptor is a Class A G-protein coupled receptor that has a high density and widespread distribution within the central nervous system. Because of its neuroanatomical distribution, the endocannabinoid system can modulate a wide variety of psychological and physiological functions. For example, CB1 receptors are found in brain regions regulating motor activity, cognitive processes, pain, satiety, appetitive behaviors and reward. In correspondence with this distribution, modulation of the endocannabinoid system has been shown to produce changes in coordination, executive function, memory, mood, perception, wakefulness, nociception and appetite. Administration of cannabinoid agonists has also been therapeutically used to reduce nausea, and is also known to decrease body temperature and neuronal excitability, pointing to additional roles for endocannabinoids in these and other physiological/neurological processes. The ongoing elucidation and characterization of the neuroanatomical circuitry within which the CB1 cannabinoid receptor and endocannabinoids are localized to modulate these psychological and physiological processes continues to suggest therapeutic applications for cannabinoid antagonists and inverse agonists. Drug Dev Res 70:527,554, 2009. © 2009 Wiley-Liss, Inc. [source]


Rapid reversal of stress induced loss of synapses in CA3 of rat hippocampus following water maze training

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 11 2003
Carmen Sandi
Abstract The impact was examined of exposing rats to two life experiences of a very different nature (stress and learning) on synaptic structures in hippocampal area CA3. Rats were subjected to either (i) chronic restraint stress for 21 days, and/or (ii) spatial training in a Morris water maze. At the behavioural level, restraint stress induced an impairment of acquisition of the spatial response. Moreover, restraint stress and water maze training had contrasting impacts on CA3 synaptic morphometry. Chronic stress induced a loss of simple asymmetric synapses [those with an unperforated postsynaptic density (PSD)], whilst water maze learning reversed this effect, promoting a rapid recovery of stress-induced synaptic loss within 2,3 days following stress. In addition, in unstressed animals a correlation was found between learning efficiency and the density of synapses with an unperforated PSD: the better the performance in the water maze, the lower the synaptic density. Water maze training increased the number of perforated synapses (those with a segmented PSD) in CA3, both in stressed and, more notably, in unstressed rats. The distinct effects of stress and learning on CA3 synapses reported here provide a neuroanatomical basis for the reported divergent effects of these experiences on hippocampal synaptic activity, i.e. stress as a suppressor and learning as a promoter of synaptic plasticity. [source]


Neurokinin 3 Receptor Immunoreactivity in the Septal Region, Preoptic Area and Hypothalamus of the Female Sheep: Colocalisation in Neurokinin B Cells of the Arcuate Nucleus but not in Gonadotrophin-Releasing Hormone Neurones

JOURNAL OF NEUROENDOCRINOLOGY, Issue 1 2010
M. Amstalden
Recent evidence has implicated neurokinin B (NKB) in the complex neuronal network mediating the effects of gonadal steroids on the regulation of gonadotrophin-releasing hormone (GnRH) secretion. Because the neurokinin 3 receptor (NK3R) is considered to mediate the effects of NKB at the cellular level, we determined the distribution of immunoreactive NK3R in the septal region, preoptic area (POA) and hypothalamus of the ewe. NK3R cells and/or fibres were found in areas including the bed nucleus of the stria terminalis, POA, anterior hypothalamic and perifornical areas, dopaminergic A15 region, dorsomedial and lateral hypothalamus, arcuate nucleus (ARC) and the ventral premammillary nucleus. We also used dual-label immunocytochemistry to determine whether a neuroanatomical basis for direct modulation of GnRH neurones by NKB was evident. No GnRH neurones at any rostral-caudal level were observed to contain NK3R immunoreactivity, although GnRH neurones and fibres were in proximity to NK3R-containing fibres. Because NKB fibres formed close contacts with NKB neurones in the ARC, we determined whether these NKB neurones also contained immunoreactive NK3R. In luteal-phase ewes, 64% ± 11 of NKB neurones colocalised NK3R. In summary, NK3R is distributed in areas of the sheep POA and hypothalamus known to be involved in the control of reproductive neuroendocrine function. Colocalisation of NK3R in NKB neurones of the ARC suggests a potential mechanism for the autoregulation of this subpopulation; however, the lack of NK3R in GnRH neurones suggests that the actions of NKB on GnRH neurosecretory activity in the ewe are mediated indirectly via other neurones and/or neuropeptides. [source]


Serotonergic and Catecholaminergic Interactions with Co-Localised Dopamine-Melatonin Neurones in the Hypothalamus of the Female Turkey

JOURNAL OF NEUROENDOCRINOLOGY, Issue 1 2009
S. W. Kang
Serotonin and catecholamines (dopamine, norepinephrine, epinephrine) have important roles as neurotransmitters in avian reproduction, but their anatomical relationship to the neuroendocrine circuitry that regulates reproduction is poorly understood. Our previous studies have shown that co-localised dopamine-melatonin (DA-MEL) neurones in the avian premammillary nucleus (PMM) are active during periods of photoresponsiveness and, therefore, are potentially photosensitive neurones. Because serotonergic and catecholaminergic neurotransmitters are important regulators of reproductive function in the female turkey, we hypothesised that the serotonergic/catecholaminergic neurones within the brainstem might interact with PMM DA-MEL neurones and constitute an important circuit for reproductive function. To examine this possible interaction, the retrograde fluorescent tract tracer, 1,1,dioctadecyl-3,3,3,3,-tetramethyleindocarbocyanine perchlorate (DiI) was injected into the PMM, and combined with serotonin, tyrosine hydroxylase (TH), dopamine ,-hydroxylase (DBH) and phenyl N -methyltransferse (PNMT) immunocytochemistry to reveal neuroanatomical connections. Changes in the activities of serotonergic, dopaminergic, adrenergic and noradrenergic neuronal systems projecting to the PMM were measured at different reproductive states with in situ hybridisation (ISH) techniques, using tryptophan hydroxylase 2 (TPH2) and TH mRNA expression, respectively. Cells labelled with DiI were found in anatomically discrete areas in or near the hypothalamus and the brainstem. Double immunocytochemistry confirmed that there were serotonin, DBH and PNMT fibres in close apposition to DA-MEL neurones. TPH2 mRNA expression in serotonin neurones was found in several nuclei, and its most abundant mRNA expression was seen in the nucleus Locus ceruleus of laying and incubating hens. TH mRNA expression levels in the six catecholaminegic areas labelled with DiI was measured across the different reproductive states. In the nucleus tractus solitarius (adrenergic), the highest level of TH mRNA expression was found in photorefractory hens and the lowest level in incubating hens. These observed patterns of serotonin/catecholamine neuronal distribution and their variable interactions with PMM DA-MEL neurones during different reproductive states may offer a significant neuroanatomical basis for understanding the control of avian reproductive seasonality. [source]