Cannabinoid CB1 receptors in rat medial prefrontal cortex are colocalized with calbindin- but not parvalbumin- and calretinin-positive GABA-ergic neurons.
Journal Title: Pharmacological Reports - Year 2009, Vol 61, Issue 6
Abstract
In the present study, we investigate putative localization of cannabinoid receptors 1 (CB1) protein on a population of cortical gamma-aminobutyric acid (GABA) - positive interneurons characterized by expression of calcium-binding proteins in rat medial prefrontal cortex (MPC). Parvalbumin (PARV)/calretinin (CALR)- and calbindin (CALB)-positive neurons form two distinct populations of GABA-ergic interneurons that comprise the axo-somatic/axo-axonic and axo-dendritic inhibitory systems of pyramidal cells. It has been found that CB1 receptor-positive cells are randomly distributed across the rat MPC. All spotted neurons that were positive for CB1 receptors were positive for GABA; however, the number of GABA-positive cells drastically exceeded the number of CB1 receptor-positive neurons. Subsequent experiments with double-labelling of CB1 receptors with PARV and CALR revealed no colocalization. CALB-positive neurons (e.g., double bouquet and bipolar cells) display colocalization: the degree of colocalization among CB1 receptor-positive cells reached 18%. The appearance of CB1 receptors in double bouquet and bipolar neurons indicates that CB1 receptors may control the activity of pyramidal neurons from presynaptic sites in axo-dendritic synapses formed on apical and basilar dendrites of pyramidal neurons, as is characteristic for CALB-positive cortical interneurons. The phenotype of GABA- and CB1 receptor-positive but CALB-negative neurons may represent a population of inhibitory neurons that allow axo-somatic control of information flow, governed by principal neurons of the MPC.
Authors and Affiliations
Krzysztof Wędzony, Agnieszka Chocyk
Guanidine-reactive agent phenylglyoxal induces DNA damage and cancer cell death.
DNA-damaging compounds (e.g., alkylating agents, cytotoxic antibiotics and DNA topoisomerase poisons) are themost widely used anticancer drugs. The inability of tumor cells to properly repair some types of DNA damage may...
Administration of L-carnitine and mildronate improves endothelial function and decreases mortality in hypertensive Dahl rats.
Hypertension is a well established risk factor for the development of cardiovascular diseases and increased mortality. This study was performed to investigate the effects of the administration of L-carnitine or mildronat...
Role of IL-6 and neopterin in the pathogenesis of herpetic encephalitis.
Herpetic encephalitis (HSE) is one of the most severe infection of the central nervous system (CNS), connected with high mortality rate, even when appropriate therapy has been introduced. Better understanding of pathomec...
Effects of bupropion on the reinstatement of nicotine-induced conditioned place preference by drug priming in rats.
Nicotine is one of the most widely consumed psychoactive drugs, and its consumption is currently associated with other drugs of abuse, such as opioids. The aim of the present study was to evaluate the efficacy of the aty...
CYP2D6 phenotyping with dextromethorphan.
Genetically determined individual differences in the ability to oxidize certain drugs have raised recently a considerable interest because of clinical importance of this problem. Determination of CYP2D6 oxidation phenoty...