Cortical GABAergic inhibitory neurons are composed of three major classes, each expressing parvalbumin (PV), somatostatin (SOM) and 5-hydroxytryptamine receptor 3A (Htr3a), respectively. Htr3a
Animals ; Interneurons/metabolism* ; Mice ; Neurons/metabolism* ; Parvalbumins/metabolism* ; Receptors, Serotonin, 5-HT3/genetics* ; Serotonin ; Somatostatin/metabolism*

OBJECTIVETo observe the expressions of Calbindin(CB) and Parvalbumin (PV), the two calcium-binding protein, in auditory pathway in mice of wild type C57BL/6J and kit⁺/kitW⁻ ²Bao, a kit gene mutant.

METHODSSix mutated kit gene kit⁺/kitW⁻ ²Bao mice and 6 wild type C57BL/6J (B6) mice were anaesthetized i. p. with chloral hydrate. After the mice were fixed by heart perfusion, the brains were removed and coronal sections were cut with a freezing microtome.

RESULTSWe found that wild type mice had significant expressions of PV on ventral cochlear nucleus, anterior part (AVCN), ventral cochlear nucleus, posterior part (PVCN), inferior colliculus (IC) and auditory cortex (AC). CB was expressed in wild type mice on PVCN and nucleus of the trapezoid body (Tz). The mutant of kit gene induced the less expression of PV on PVCN, IC and AC (P < 0.01), but increased the expression of Tz (P < 0.01). CB could not be observed on PVCN in mutant mice, and the expression of AC was increased( P < 0.01).

CONCLUSIONCB and PV has differential expression level in auditory pathway. Since mutated kit gene can affect expression of PV on PVCN, IC, Tz and AC, as well as CB on PVCN and AC, it suggests that the mutation of kit gene can affect the advanced function of central nervous system in auditory pathway.

Animals ; Auditory Cortex ; metabolism ; Auditory Pathways ; metabolism ; Calbindins ; metabolism ; Inferior Colliculi ; metabolism ; Mice ; Mice, Inbred C57BL ; Mutation ; Parvalbumins ; metabolism ; Pons ; metabolism ; Proto-Oncogene Proteins c-kit ; genetics

OBJECTIVETo evaluate the alteration of subunits composition in NMDA receptor and the alterations of the expression and distribution of NMDA receptors and parvalbumin (PV)-positive neurons in focal cortical dysplasia (FCD) cortices.

METHODSTwenty cases of FCD samples (including all four subtypes of FCD) obtained during epilepsy surgery and 4 controls were analysed by immunohistochemical staining for NR1, NR2A/B and PV.

RESULTSIncreased expression of NR1 was detected in the giant neurons and dysmorphic neurons in FCD; while pronounced expression of NR2A/B was detected in immature neurons, giant neurons and dysmorphic neurons of FCD, especially in somata and processes of the immature neurons. Compared with the controls, FCD cortices showed prominent scattered arrangement of PV positive neurons and fibers, dramatically decreased number of PV positive interneurons and PV background staining, especially in foci of FCD II subtype.

CONCLUSIONThere are increased expressions of NR1 and NR2A/B subunits in FCD abnormal neurons, as well as scattered and reduced expressions of PV positive neurons and fibers in FCD cortices.

Adolescent ; Biomarkers, Tumor ; metabolism ; Cerebral Cortex ; metabolism ; pathology ; Child ; Child, Preschool ; Epilepsies, Partial ; pathology ; Female ; Gene Expression Regulation ; Humans ; Infant ; Interneurons ; metabolism ; Male ; Malformations of Cortical Development ; pathology ; Neurons ; metabolism ; Parvalbumins ; analysis ; isolation & purification ; Receptors, N-Methyl-D-Aspartate ; genetics ; metabolism

The hippocampus is affected by various stimuli that include hyperglycemia, depression, and ischemia. Calcium-binding proteins (CaBPs) have protective roles in the response to such stimuli. However, little is known about the expression of CaBPs under diabetic conditions. This study was conducted to examine alterations in the physiological parameters with type 1 diabetes induced with streptozotocin (STZ) as well as time-dependent changes in the expression of two CaBPs changes of were being evaluated. Rats treated with STZ (70 mg/kg) had high blood glucose levels (>21.4 mmol/L) along with increased food intake and water consumption volumes compared to the sham controls. In contrast, body weight of the animals treated with STZ was significantly reduced compared to the sham group. CB-specific immunoreactivity was generally increased in the hippocampal CA1 region and granule cell layer of the dentate gyrus (DG) 2 weeks after STZ treatment, but decreased thereafter in these regions. In contrast, the number of PV-immunoreactive neurons and fibers was unchanged in the hippocampus and DG 2 weeks after STZ treatment. However, this number subsequently decreased over time. These results suggest that CB and PV expression is lowest 3 weeks after STZ administration, and these deficits lead to disturbances in calcium homeostasis.
Animals ; Calbindin 1/*genetics/metabolism ; Diabetes Mellitus, Experimental/*chemically induced ; Diabetes Mellitus, Type 1/*chemically induced ; *Gene Expression Regulation ; Hippocampus/*metabolism ; Male ; Parvalbumins/*genetics/metabolism ; Rats ; Rats, Wistar ; Streptozocin/administration & dosage

Inhibitory GABAergic interneurons are fundamental elements of cortical circuits and play critical roles in shaping network activity. Dysfunction of interneurons can lead to various brain disorders, including epilepsy, schizophrenia, and anxiety. Based on the electrophysiological properties, cell morphology, and molecular identity, interneurons could be classified into various subgroups. In this study, we investigated the density and laminar distribution of different interneuron types and the co-expression of molecular markers in epileptic human cortex. We found that parvalbumin (PV) and somatostatin (SST) neurons were distributed in all cortical layers except layer I, while tyrosine hydroxylase (TH) and neuropeptide Y (NPY) were abundant in the deep layers and white matter. Cholecystokinin (CCK) neurons showed a high density in layers IV and VI. Neurons with these markers constituted ~7.2% (PV), 2.6% (SST), 0.5% (TH), 0.5% (NPY), and 4.4% (CCK) of the gray-matter neuron population. Double- and triple-labeling revealed that NPY neurons were also SST-immunoreactive (97.7%), and TH neurons were more likely to express SST (34.2%) than PV (14.6%). A subpopulation of CCK neurons (28.0%) also expressed PV, but none contained SST. Together, these results revealed the density and distribution patterns of different interneuron populations and the overlap between molecular markers in epileptic human cortex.
Adolescent ; Adult ; Brain Chemistry ; genetics ; physiology ; Cerebral Cortex ; metabolism ; pathology ; Child ; Cholecystokinin ; metabolism ; Epilepsy ; etiology ; pathology ; Female ; Gene Expression Regulation ; physiology ; Humans ; Interneurons ; metabolism ; Male ; Middle Aged ; Neuropeptide Y ; metabolism ; Parvalbumins ; metabolism ; Phosphopyruvate Hydratase ; metabolism ; Somatostatin ; metabolism ; Tyrosine 3-Monooxygenase ; metabolism ; Young Adult