INTRASTRIATAL KAINIC ACID - ACUTE EFFECTS ON ELECTRO-PHYSIOLOGICAL AND BIOCHEMICAL MEASURES OF NIGROSTRIATAL DOPAMINERGIC ACTIVITY

  • 1 January 1981
    • journal article
    • research article
    • Vol. 216  (2) , 289-293
Abstract
The acute effects of intrastriatal kainic acid injection on rat nigrostriatal dopamine cell activity were assessed using electrophysiological and biochemical techniques. One h after kainic acid injection, dopamine cell firing rates were significantly increased, as were striatal dopamine synthesis (dopa accumulation) and dopamine metabolism (3,4-dihydroxyphenylacetic acid (DOPAC) levels). Postkainic acid administration (12 h), cell firing rate had returned to control levels, as had dopa accumulation and DOPAC levels, but the number of dopamine cells firing had significantly decreased. Action potentials were elicited from silent dopamine cells by iontophoretic application of GABA but not glutamate. After kainic acid (48 h) the number of dopamine cells firing was significantly increased, as were DOPAC levels. Both cell firing rate and dopa accumulation matched control values. The results are discussed in terms of the role of strionigral pathways in mediating the acute effects of kainic acid on the nigrostriatal dopaminergic system and recently described phenomenon of presumed dopamine cell depolarization inactivation.