DIFFERENTIAL DISTRIBUTION OF DYSTROPHIN IN POSTSYNAPTIC DENSITIES OF SPINE SYNAPSES

DYSTROPHIN immunocytochemistry was carried out using monoclonal antibo dy against the C-terminal part of dystrophin (Dys2) in rat cerebral co rtex, cerebellum and hippocampus containing a high number of spine syn apses of similar morphological character. Dys2 immunoreactivity was fo und in the spine component of spine synapses. Particularly heavy label was observed on the postsynaptic densities. In the cerebral and cereb ellar cortices all spines were immunopositive. In the hippocampus some postsynaptic densities were intensely immunostained, whereas those of adjacent synapses remained unstained. The findings suggest that dystr ophin is an integral protein of the postsynaptic component of spine sy napses but is lacking in a subpopulation of hippocampal spine synapses . The heterogeneity of input to the hippocampal spiny sites by contras t to the homogeneous population of fibres synapsing with cerebral and cerebellar cortical spines is suggested to account for differences. Ne uro Report 9: 2249-2251 (C) 1998 Rapid Science Ltd.