Release of glutamate by the embryonic spinal motoneurons of rat positively regulated by acetylcholine through the nicotinic and muscarinic receptors.

It has been shown that mature neurons in adult vertebrates can co-express glutamate and acetylcholine. Furthermore, interactions at the synaptic level have been demonstrated. In a previous study we found that also motoneurons at early embryonic stages, thus well prior to synapse formation, release acetylcholine, and that glutamate increases this release.

Involvement of the alpha 7 subunit of the nicotinic receptor in morphogenic and trophic effects of acetylcholine on embryonic rat spinal motoneurons in culture.

The morphogenic and trophic effects of acetylcholine (ACh) on embryonic cultured rat spinal cord motoneurons (MNs) through nicotinic alpha7 autoreceptors were assessed. Alpha7 Subunits of the nicotinic cholinergic receptor were detected in cultures of purified rat spinal embryonic MNs sampled at E15, by both immunocytochemistry and alpha-bungarotoxin binding. According to these two methods, alpha7 subunits are located mainly at somatic and axonal membrane.

Expression and distribution of phocein and members of the striatin family in neurones of rat peripheral ganglia.

Phocein and members of the striatin family (striatin, SG2NA and zinedin) are intracellular proteins, mainly expressed in neurones of the mammalian central nervous system where they are thought to be involved in vesicular traffic and Ca(2+) signalling. Here, we have investigated whether these proteins are also present in the peripheral nervous system, by analysing their expression and distribution within sensory neurones of the vagal (nodose and jugular) ganglia, the petrosal ganglion, the dorsal root ganglion, and also in the sympathetic neurones of the superior cervical ganglion. RT-PCR experiments showed that mRNAs of phocein, striatin, SG2NA and zinedin are present in all studied peripheral ganglia.

Effect of quercetine on survival and morphological properties of cultured embryonic rat spinal motoneurones.

Quercetine a flavonoid compound present in many plants and in the extract of Ginkgo biloba was shown to enhance the survival of purified rat spinal embryonic motoneurones, sampled at day embryonic 15 and maintained in culture for several days. Survival of embryonic spinal motoneurones is dose dependent and concentrations of quercetine ranging from 1 to 10 microM increase by 25% the number of living motoneurones in the culture. Excepted a slight significant decrease in the number of branches at day 3 and a small reduction of total neuritic length, no drastic changes in the motoneurones morphologies were observed in presence of quercetine.

Effects of temperature on the early stages of rat spinal motoneurone development in vitro.

Effects of temperature on rat spinal motoneurone morphogenesis during the early stages of development were investigated in vitro through a statistical morphometric analysis, and examined in the frame of a basic theoretical aggregation growth model. Morphological measurements in the 31.0-39.