The α2A adrenoceptors (α2A-ARs) are the most common adrenergic receptor subtype found in the prefrontal cortex (PFC). It is generally accepted that stimulation of postsynaptic α2A-ARs on pyramidal neurons are key to PFC functions, such as working memory. However, the expression of α2A-ARs in interneurons is largely unknown. In the present study using double-labeling immunofluorencence technique, we investigated the expression of α2A-ARs in major types of rat PFC interneurons expressing calcium-binding proteins parvalbumin (PV), calretinin (CR), and calbindin (CB). Our data demonstrated that α2A-ARs are highly expressed in calcium-binding protein immunoreactive interneurons of rat PFC, suggesting that stimulation of α2A-ARs may alter neural networks comprising pyramidal neurons and interneurons, thereby exerting a beneficial effect on PFC cognitive functions. The present study provides the morphological basis for a potential mechanism by which stimulation of α2A-ARs induces cognitive improvement.
Animals ; Calbindin 2 ; metabolism ; Calbindins ; metabolism ; Interneurons ; metabolism ; Parvalbumins ; metabolism ; Prefrontal Cortex ; cytology ; Rats ; Receptors, Adrenergic, alpha-2 ; metabolism

The purpose of this study was to identify specific microRNAs (miRNAs) during differentiation and maturation of interneurons and to predict their possible functions by analyzing the expression of miRNAs during in vitro differentiation of the rat interneuron precursor cell line GE6. In the experiment, the interneuron precursor cell line GE6 was cultured under three different conditions, i. e. the first was that had not added growth factors and the normal differentiation cultured for 4 days (Ge6_4d); the second was that cultured with bone morphogenetic protein-2 (BMP2) for 4 days (Ge6_bmp2); and the third was that cultured with sonic hedgehog (SHH) for 4 days (Ge6_ shh). In addition, another group of undifferentiated GE6 (Ge6_u) was applied as a control. We found in this study that the expression levels of a large number of miRNAs changed significantly during GE6 differentiation. The expression levels of miR-710, miR-290-5p and miR-3473 increased in the GE6 cells with secreted factor BMP2. These miRNAs may play important regulatory roles during interneuron differentiation.
Animals ; Bone Morphogenetic Protein 2 ; chemistry ; Cell Differentiation ; Cell Line ; Hedgehog Proteins ; chemistry ; Interneurons ; cytology ; metabolism ; MicroRNAs ; metabolism ; Rats

The present study is aimed to investigated the firing activity of pyramidal neurons and interneurons in the medial prefrontal cortex (mPFC) in rats with bilateral intraventricular injection of 5,7-dihydroxytryptamine (5,7-DHT) by using in vivo extracellular recording. The results showed that the injection of 5,7-DHT reduced the 5-hydroxytryptamine (5-HT) levels in the mPFC and dorsal raphe nucleus in the rats. The firing rate of mPFC pyramidal neurons in rats with 5,7-DHT injection was significantly higher than that of normal rats, and the firing pattern of these neurons also changed significantly towards a more burst-firing, while the injection decreased the firing rate of mPFC interneurons and changed the firing pattern of the interneurons towards a more irregular. These results indicate that the lesions of the serotonergic neurons lead to the changes in the firing activity of mPFC pyramidal neurons and interneurons, suggesting that serotonergic system plays an important role in the regulation of the neuronal activity in the mPFC.
5,7-Dihydroxytryptamine ; pharmacology ; Action Potentials ; Animals ; Dorsal Raphe Nucleus ; cytology ; Injections, Intraventricular ; Interneurons ; drug effects ; Prefrontal Cortex ; cytology ; Pyramidal Cells ; drug effects ; Rats ; Serotonin ; metabolism

PURPOSE: c-fos expression in spinal neurons that are activated by lower urinary tract stimulation are not organ specific. In this experiment, we demonstrated changes of c-fos expression in bladder-specific preganglionic neurons (PGNs) and interneurons using pseudorabies virus (PRV). MATERIALS AND METHODS: Forty Sprague-Dawley rats were used. We identified the neuronal pathway associated with the bladder by injecting PRV into the detrusor. An immunohistochemical method was used to stain Fos-protein encoded by the c-fos gene. Immunofluorescent staining for PRV was performed to evaluate changes in bladder-specific spinal neurons. RESULTS: Immunofluorescent staining with choline acetyltransferase (ChAT) revealed that the sacral parasympathetic nucleus (SPN) regions contained 9.8 PGNs/ section. In rats with chronic spinal cord injury by intravesical saline instillation, 82.4+/-10.3% of PGNs in SPN exhibited Fos-immunoreactive (IR). Two and a half days after PRV infection, PRV-IR PGNs were observed at 5.4 PGNs/ section, and 2.7+/-1.6% of them exhibited Fos-IR. Unlike ChAT-IR PGNs, PRV-IR PGNs are bladder-specific neurons and PRV-IR and Fos-IR cells found in the back of PRV-IR PGNs are bladder- specific interneurons. Three days after PRV infection, we observed many PRV-IR and Fos-IR cells in the dorsal commissure. These neurons are interneurons distributed in the bladder. CONCLUSION: We confirmed that in chronic spinal cord injury, the patterns of c-fos expression in bladder-specific spinal neurons were similar to those in voiding-reflex related spinal neurons, which had already been demonstrated earlier. We believe that our methodology can be applied to study interactions between voiding and other organs as well, such as the urethra and prostate.
Animals ; Female ; Herpesvirus 1, Suid/*physiology ; Immunohistochemistry ; Interneurons/cytology/metabolism ; Neurons/cytology/*metabolism ; Proto-Oncogene Proteins c-fos/*metabolism ; Rats ; Rats, Sprague-Dawley ; Spinal Cord Injuries/*physiopathology ; Urinary Bladder/cytology/*metabolism/virology

OBJECTIVE: To investigate the axonal sprouting of somatostatin(SS) positive interneurons in temporal lobe epilepsy. METHODS: 6-8 week-old healthy male SD rats were divided randomly into an epileptic group (treated by lithium and pilocarpine intraperitoneal injection) and a control group (by lithium and normal sodium intraperitoneal injection). Each group was randomly divided into 5 subgroups at 1,7,15,30, amd 60 d after the injection. Immunohistochemistry method was used to detect the number changes of SS or neuronal nuclei (NeuN) positive neurons in different domains of the hippocampus at different time points in each group, and the coexpression of SS positive interneurons combined with NeuN was detected by double immunofluorescence to observe the dynamic changes and axonal sprouting of SS positive interneurons. RESULTS: The number of SS neurons in the experimental group exceeded that in the control group in the CA1 area at 60 d post-status epileptieus SE (P<0.01), and numerous SS positive fibers were seen throughout the layers of the CAl area at 60 d post-SE. NeuN positive neurons in the stratum oriens and stratum radiatum layers in the initiation site of the CA1 area were beyond normal at 60 d post-SE. The number of double labeled SS interneurons gradually rose at 15 d in stratum oriens of CA1, and even exceeded that of the controls in the stratum oriens and stratum radiatum layers of CA1 at 60 d. CONCLUSION The numerous SS positive fibers throughout the layers of the CAl area at 60 d post-SE come from the increased interneurons in the stratum oriens and stratum radiatum layers of CA1 area. The pathological axonal sprouting may play an important role in the generation and compensation of temporal lobe epilepsy.
Animals ; Axons ; metabolism ; pathology ; CA1 Region, Hippocampal ; cytology ; metabolism ; physiopathology ; Efferent Pathways ; pathology ; physiology ; Epilepsy, Temporal Lobe ; chemically induced ; metabolism ; physiopathology ; Interneurons ; cytology ; metabolism ; pathology ; Male ; Pilocarpine ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Somatostatin ; metabolism ; Temporal Lobe ; metabolism