CHANGES IN GABA AND PARVALBUMIN IMMUNOREACTIVITIES IN THE CEREBRAL-CORTEX OF LIZARDS AFTER NARINE OCCLUSION

Olfactory deprivation produced by narine occlusion has been suggested to reduce the activity in the cerebral cortex of lizards. Here we anal yzed the short-term changes in GABA and parvalbumin (PV) immunoreactiv ities in the cerebral cortex of lizards after narine occlusion. The nu mber and distribution of GABA- and parvalbumin-immunoreactive (IR) cel ls have been studied by immunocytochemistry in the cerebral cortex of control and olfactory-deprived lizards. The distribution of GABA-IR ce lls as well as that of PV-IR cells was similar in control and deprived animals, and PV-IR cells were GABA-IR in all cases. However, signific ant changes were observed in the absolute number of GABA- and PV-IR ce lls. GABA-IR cells were more abundant in deprived animals than in cont rol ones. In contrast, the number of PV-IR cells decreased significant ly and PV immunoreactivity in dendrites and boutons was lower in depri ved animals. These results suggest that the reduction in the number of PV-IR cells in olfactory-deprived lizards occurs without loss of GABA cells, and that PV expression is under the control of olfactory activ ity and remains plastic in the cerebral cortex of adult lizards.