EFFECTS OF TETRODOTOXIN TREATMENT IN LGN ON NEUROMODULATORY RECEPTOR EXPRESSION IN DEVELOPING VISUAL-CORTEX

The expression and distribution patterns of transmitter receptors chan ge dramatically during pre-and post-natal development of the visual co rtex, but the factors that control these processes are largely unknown . We have tested the hypothesis that input activity from the lateral g eniculate nucleus (LGN), one major input source to visual cortex, may contribute to the processes underlying transmitter receptor redistribu tions in the visual cortex during development. We found that a short p eriod of tetrodotoxin (TTX) treatment in LGN retarded the developmenta l expression and age-dependent reorganization of neuromodulatory recep tors, including muscarinic, serotonergic and adrenergic receptors, in kitten primary visual cortex. The visual cortices ipsilateral to the T TX infusion site displayed a 'younger' receptor pattern than that of t heir contralateral control counterparts in the same animals. The resul ts suggest that active input from LGN regulates the expression profile of a broad range of receptors in the developing visual cortex. (C) 19 98 Elsevier Science B.V.