The Absence of the Transient Receptor Potential Vanilloid 1 Directly Impacts on the Expression and Localization of the Endocannabinoid System in the Mouse Hippocampus.

The transient receptor potential vanilloid 1 (TRPV1) is a non-selective ligand-gated cation channel involved in synaptic transmission, plasticity, and brain pathology. In the hippocampal dentate gyrus, TRPV1 localizes to dendritic spines and dendrites postsynaptic to excitatory synapses in the molecular layer (ML). At these same synapses, the cannabinoid CB receptor (CBR) activated by exogenous and endogenous cannabinoids localizes to the presynaptic terminals.

Dopaminergic denervation impairs cortical motor and associative/limbic information processing through the basal ganglia and its modulation by the CB1 receptor.

The basal ganglia (BG) are involved in cognitive/motivational functions in addition to movement control. Thus, BG segregated circuits, the sensorimotor (SM) and medial prefrontal (mPF) circuits, process different functional domains, such as motor and cognitive/motivational behaviours, respectively. With a high presence in the BG, the CB1 cannabinoid receptor modulates BG circuits.

Endocannabinoid long-term depression revealed at medial perforant path excitatory synapses in the dentate gyrus.

The endocannabinoid system modulates synaptic plasticity in the hippocampus, but a link between long-term synaptic plasticity and the type 1 cannabinoid (CB) receptor at medial perforant path (MPP) synapses remains elusive. Here, immuno-electron microscopy in adult mice showed that ∼26% of the excitatory synaptic terminals in the middle 1/3 of the dentate molecular layer (DML) contained CB receptors, and field excitatory postsynaptic potentials evoked by MPP stimulation were inhibited by CB receptor activation. In addition, MPP stimulation at 10 Hz for 10 min triggered CB receptor-dependent excitatory long-term depression (eCB-eLTD) at MPP synapses of wild-type mice but not on CB-knockout mice.

Localization of the cannabinoid type-1 receptor in subcellular astrocyte compartments of mutant mouse hippocampus.

Astroglial type-1 cannabinoid (CB ) receptors are involved in synaptic transmission, plasticity and behavior by interfering with the so-called tripartite synapse formed by pre- and post-synaptic neuronal elements and surrounding astrocyte processes. However, little is known concerning the subcellular distribution of astroglial CB receptors. In particular, brain CB receptors are mostly localized at cells' plasmalemma, but recent evidence indicates their functional presence in mitochondrial membranes.

Conserved cellular distribution of the glutamate receptors GluA2/3, mGlu1a and mGlu2/3 in isolated cultures of rat cerebellum.

To what extent the intrinsic glutamatergic system of the cerebellum is able to keep normal features in the absence of mossy and climbing fibres, is at present not known. To answer this question, immunocytochemistry for light and high resolution electron microscopy was used to reveal the cellular and subcellular distribution of glutamate receptors in isolated cerebellar cultures. The localization of the ionotropic glutamate receptor subunits GluA2/3 and the metabotropic glutamate (mGlu) 1a and mGlu2/3 receptor subtypes was carried out in 0 to 9-day-old rat parasagittal slices developed in vitro for 20-40 days.

Involvement of subthalamic nucleus in the stimulatory effect of Delta(9)-tetrahydrocannabinol on dopaminergic neurons.

The cannabinoid CB1 receptor which is densely located in the basal ganglia is known to participate in the regulation of movement. The present study sought to determine the mechanisms underlying the effect of Delta(9)-tetrahydrocannabinol (Delta(9)-THC) on neurons in the substantia nigra pars compacta (SNpc) using single-unit extracellular recordings in anesthetized rats. Administration of Delta(9)-THC (0.

Plasticity of basal ganglia neurocircuitries following perinatal asphyxia: effect of nicotinamide.

The potential neuroprotection of nicotinamide on the consequences of perinatal asphyxia was investigated with triple organotypic cultures. Perinatal asphyxia was induced in vivo by immersing foetuses-containing uterine horns removed from ready-to-deliver rats into a water bath for 20 min. Sibling caesarean-delivered pups were used as controls.

Electrophysiological characterization of substantia nigra dopaminergic neurons in partially lesioned rats: effects of subthalamotomy and levodopa treatment.

Progressive degeneration of dopaminergic neurons in the substantia nigra pars compacta is the main histopathological characteristic of Parkinson's disease. We studied the electrophysiological characteristics of the spontaneous activity of substantia nigra pars compacta dopaminergic neurons in rats with a partial, unilateral, 6-hydroxydopamine lesion of the nigrostriatal pathway. In addition, the effects of subthalamotomy and prolonged levodopa treatment on the activity of dopaminergic neurons were investigated.

Cerebral blood flow and morphological changes after hypoxic-ischaemic injury in preterm lambs.

Aim: To evaluate the effect of cerebral hypoxia-ischaemia induced by partial occlusion of the umbilical cord on the relationship of the regional cerebral blood flow and the cerebral cell death in near-term fetal lambs.

Methods: Fifteen near-term lambs were assigned to two hypoxic-ischaemic groups with or without life support (3 h), and a healthy one. Hypoxia-ischaemia was induced by partial occlusion of the umbilical cord (60 min).

Characterization of noradrenaline release in the locus coeruleus of freely moving awake rats by in vivo microdialysis.

Rationale: The origin and regulation of noradrenaline (NA) in the locus coeruleus (LC) is unknown.

Objectives: The neurochemical features of NA overflow (nerve impulse dependence, neurotransmitter synthesis, vesicle storage, reuptake, alpha2-adrenoceptor-mediated regulation) were characterized in the LC.

Methods: Brain microdialysis was performed in awake rats.

Cells from the inner mass of blastocyst as a source of neural derivates for differentiation studies.

Our results show that cells derived from the inner cell mass (ICM) show a clear tendency to differentiate into the neural lineage, showing both cells and structures in different degrees of differentiation. Among the experimental paradigms used to learn about neural differentiation, there have been several lines of investigation on stem cells, including embryonic stem (ES) cells isolated from the inner cell mass of embryo and also stem cells derived from embryonic carcinoma (EC). In this work, we have used a cellular line obtained from the inner cell mass of a blastocyst.

Perinatal asphyxia impairs connectivity and dopamine neurite branching in organotypic triple culture from rat substantia nigra, neostriatum and neocortex.

The effect of perinatal asphyxia on brain development was studied with organotypic cultures from substantia nigra, neostriatum and neocortex. Asphyxia was induced by immersing foetuses-containing uterine horns removed from ready-to-deliver rats into a water bath for 20 min. Following asphyxia, the pups were nursed by a surrogate dam and sacrificed after 3 days to prepare organotypic cultures.

Excitatory amino acids, monoamine, and nitric oxide synthase systems in organotypic cultures: biochemical and immunohistochemical analysis.

The nigrostriatal and mesolimbic systems of the rat have been re-constructed using the organotypic culture model, whereby neonatal brain tissue is grown in vitro for approximately one month. The nigrostriatal cultures consisted of tissue from the substantia nigra, dorsal striatum and frontoparietal cortex; while the mesolimbic cultures included the ventral tegmental area, ventral striatum and cingulate cortex. The cultures were grown at 35 degrees C in normal atmosphere, using a tuberoller device placed in a cell incubator and changing the medium every 3-4 days.

GABAergic neurons in the rabbit visual cortex: percentage, layer distribution and cortical projections.

6250 neurons yielding either callosal or inter-areal ipsilateral projections extrinsic to area 17 was GABAergic. Comparing these findings with those reported for other mammals, it seems that the incidence and distribution of GABAergic neurons in the visual cortex is similar in rabbits and rats. In contrast to rats but akin to higher mammals, no GABAergic neuron was found to furnish cortico-cortical connections to area 17 other than intrinsic connections.

Percentage incidence of gamma-aminobutyric acid neurons in the claustrum of the rabbit and comparison with the cortex and putamen.

We describe the incidence of gamma-aminobutyric acid (GABA)ergic neurons after post-embedding immunocytochemistry on semithin sections of the claustrum, putamen and lateral, dorsal and medial cortical areas. Twelve percent of the neurons counted in the claustrum of 11 rabbits were GABAergic. This incidence was significantly higher in the dorsal halves of both the insular and endopiriform claustra than in the ventral (13 vs.

Neurocircuitries of the basal ganglia studied in organotypic cultures: focus on tyrosine hydroxylase, nitric oxide synthase and neuropeptide immunocytochemistry.

The nigrostriatal and mesolimbic systems of the rat were reconstructed using an organotypic culture model, whereby neonatal brain tissue was grown in vitro for approximately one month. The nigrostriatal system comprised of tissue from the substantia nigra, the dorsal striatum and the frontoparietal cortex, while the mesolimbic system included the ventral tegmental area, ventral striatum (including the fundus striati, accumbens nucleus, olfactory tubercle, lateral septum, ventral pallidum and piriform cortex) and cingulate cortex. These regions were also cultured alone or in pairs.

Widespread Horizontal Connections Arising from Layer 5/6 Border Inverted Cells in Rabbit Visual Cortex.

Herein we describe the inverted cells [defined as those projection neurons having a major dendritic shaft abpially oriented (Bueno-López et al., Eur. J.

Targets and Laminar Distribution of Projection Neurons with 'Inverted' Morphology in Rabbit Cortex.

This study examines the axonal projections of so-called inverted pyramids and other neurons with their major dendritic shaft oriented in the direction of the white matter ('inverted cells') in the adult rabbit cortex. Single injections of horseradish peroxidase wheat germ agglutinin were made into cortical or subcortical sites. The resulting retrograde labelling in the cortex was analysed and the distribution across areas and layers of inverted cells contributing to each of these projections was estimated.