Electroconvulsive shock increases dopamine D1 and D2 receptor mRNA in the nucleus accumbens of the rat.

The present study examined the effects of acute and repeated administration of electroconvulsive shock (ECS) on levels of D1 and D2 receptor mRNAs in the nucleus accumbens and striatum (caudate-putamen) of the rat. Quantitative in situ hybridisation with 35S-labelled oligonucleotide probes specific for D1 and D2 receptor mRNAs was utilised. Compared to controls, rats receiving a single ECS showed higher levels of both D1 and D2 receptor mRNAs in the nucleus accumbens 4 h, but not 24 h, after treatment. Similarly, rats receiving ECS repeatedly (five ECS in 10 days) also exhibited higher levels of D1 and D2 receptor mRNAs in the nucleus accumbens 4 h, but not 24 h, after the last treatment. The effects of single and repeated ECS treatment on dopamine receptor mRNA levels were localised to the caudal region of the nucleus accumbens. No statistically significant changes in mRNA levels were detected in the striatum of rats treated with either acute or repeated ECS. We discuss the possibility that increased expression of D1 and D2 receptors in the nucleus accumbens may be involved in the dopamine-enhancing properties of ECS detected in behavioural studies.