Catecholaminergic neurons, effects

Akaoka H., Roussel B., Lin J. S., Chouvet G., Jouvet M. (1991). Effect of modafinil and amphetamine on the rat catecholaminergic neuron activity. Neurosci Lett. 123, 20-2. 

However, receptor autoradiography and in vitro studies have suggested that H3 receptors are located on other aminergic neurons in the brain. Since amines such as serotonin and catecholamines are involved in the regulation of pituitary hormone secretion, it is obvious that an action of the H3 receptor compounds may be exerted via these H3 heteroreceptors. Only few studies have evaluated this heteroreceptor action. It has been excluded that the effect of the H3 receptor agonists is due to an effect on H3 receptors located on serotonergic neurons, while an effect on catecholaminergic neurons has yet not been excluded. 

To test a compound s ability to enhance the acquisition of CARs in the shuttle box, it is necessary to select proper training conditions. In the case in which the rat was trained with 100 trials per day, the acquisition of CARs reached an 80% level and the EFs approached or reached the zero level. To demonstrate the highly significant enhancer effect of (-)-BPAP on the mesencephalic catecholaminergic neurons in vivo, we trained the rat with 100 trials per day, blocked the acquisition of CARs by pretreating the rats with tetrabenazine, and restored the learning ability with the simultaneous administration of (-)-BPAP. Table 3.1 shows that (-)-BPAP antagonized the effect of tetrabenazine in the rats. 

Table 3.1. Because of its enhancer effect on catecholaminergic neurons, (-)-BPAP antagonized tetrabenazine-induced learning deficit in rats trained in the shuttle box...

Effects on cultured catecholaminergic neurons during development... 

Unfortunately, because it is not possible to isolate dopaminergic neurons for culture from embryos older than El8, the age-dependence of these effects could not be directly tested as it had been in non-catecholaminergic neurons. However, in our initial studies with MDF, in situ infusion into the adult intact rat (Fig. 3) produced none of the changes observed in developing neurons, with no detectable increments in TH activity, DA or 3,4-dihydroxyphenylacteic acid (DOPAC) levels (Jin and lacovitti, 1995). In addition, the localization of... 

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