Correlating Physiology with Gene Expression in Striatal Cholinergic Neurones

: The expression of 34 transmitter‐related genes has been examined in the cholinergic neurones of rat striatal brain slices, with the aim of correlating gene expression with functional activity. The mRNAs encoding types I, II/IIA, and III α subunits of the voltage‐sensitive sodium channels were detected, suggesting the presence of these three types of sodium channel. Similarly, mRNAs encoding all four α‐amino‐3‐hydroxy‐5‐methyl‐isoxazole‐4‐propionate (AMPA)‐type glutamate receptor subunits and the NR1 and NR2A, 2B, and 2D subunits of the NMDA‐type glutamate receptors were detected, suggesting that various combinations of these subunits mediate the cellular response to synaptically released glutamate. Other mRNAs detected included the NK1 and NK3 tachykinin receptors, all four known adenosine receptors, and the GABA‐synthesising enzyme glutamate decarboxylase. Subpopulations of these cholinergic neurones have been identified on the basis of the expression of the NK3 tachykinin receptor in 5% and the trkC neurotrophin receptor in 12% of the cells investigated.