Co-expression of calretinin and gamma-aminobutyric acid in neurons of the entorhinal cortex of the common marmoset monkey.
The gamma-aminobutyric acid (GABA)-containing interneuron population in the entorhinal cortex has been shown to consist of several subpopulations. In addition to GABA, these neurons contain another neurochemical substance, such as a neuropeptide or a calcium binding protein. In the present study, we examined the co-localization of calretinin and GABA in the entorhinal cortex of the common marmoset Callithrix jacchus, a New World monkey. Although the function of calretinin remains unclear, there are indications that it might have a protective role against cell death in a number of neuropathological diseases. Furthermore, it might have a regulatory role in the neurotransmission of GABAergic neurons. In contrast to the rat brain, sparse data exist regarding the degree of co-expression of these two markers in the monkey brain. Using immunofluorescence and confocal laser scanning microscopy, we found that an average of 56% of the calretinin-positive neurons in the monkey entorhinal cortex contained GABA, whereas about 27% of the GABA-positive neurons co-expressed calretinin. Interestingly, these numbers were higher in the superficial layers of the entorhinal cortex in comparison with the deep layers. However, no differences were found in co-localization percentages between the different entorhinal subfields. In general, the degree of co-localization was higher in comparison to findings in the rat entorhinal cortex. The higher amount of co-localization observed in the present study might reflect species differences between the primate and the non-primate brain.
Behavioral Neurobiology Laboratory, Swiss Federal Institute of Technology Zurich, Schwerzenbach, Switzerland.
Helen H J
HH
Pothuizen
Joram
J
Feldon
Ana L
AL
Jongen-Rêlo
D000818:Animals; D064032:Calbindin 2; D002144:Callithrix; D002470:Cell Survival / Q000502:physiology; D018728:Entorhinal Cortex / Q000033:anatomy & histology / Q000166:cytology / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D007395:Interneurons / Q000166:cytology / Q000378:metabolism*; D008297:Male; D018613:Microscopy, Confocal; D018696:Neuroprotective Agents / Q000378:metabolism; D051381:Rats; D064030:S100 Calcium Binding Protein G / Q000096:biosynthesis*; D013045:Species Specificity; D009435:Synaptic Transmission / Q000502:physiology; D005680:gamma-Aminobutyric Acid / Q000096:biosynthesis*
C576512:Calb2 protein, rat; D064032:Calbindin 2; D018696:Neuroprotective Agents; D064030:S100 Calcium Binding Protein G; D005680:gamma-Aminobutyric Acid