[SECOND MESSENGERS IN PRESYNAPTIC REGULATION OF GLYCINERGIC SYNAPSE ON THE FROG MOTONEURON].

The possible pathways of inhibitory influences mediated by two kinds of metabotropic receptors, group III metabotropic glutamate receptors (mGluRs III) and GABAB receptors (GABABRs) to the miniature glycinergic events were investigated in the isolated spinal cord of the frog Rana ridibunda. The glycinergic events prevailed within the miniature inhibitory activity of motoneurons [3]. Selective agonists of GABABRs (baclofen) and group III mGluR (LAP4) reduce the frequency of miniature events to 48.

[Dorsal root afferent fiber termination in the spinal cord of the turtle Testudo horsfieldi and 3-dimensional reconstruction of the sensory-motoneuron connection].

HRP tracing methods and computer reconstruction were used to study the structural organization of sensory-motoneuron connections in the turtle. HRP was applied through suction electrodes to thin dorsal and ventral root filaments of superfused isolated lumbar spinal cord of the turtle Testudo horsefieldi. Single motoneurons were labeled iontophoretically with the use of intracellular glass microelectrodes.

[The role of group II and III metabotropic glutamate receptors in modulation of miniature synaptic activity in frog spinal cord motoneurons].

The results of present work demonstrate significant modulating effects mediated by group II and III mGluRs on miniature postsynaptic potentials (mPSP) of the frog spinal motoneurons. The mode of group II and III mGluRs ligands influences, i. e.

Comparative study of spinal motoneuron axon collaterals.

Numerous spinal motoneurons in mammals possess recurrent axon collaterals included in a feedback loop for controlling motoneuron activity. For nonmammalian vertebrates, the data concerning the existence of collaterals and their intraspinal branching are fragmentary and contradictory. We focused on axonal branching of motoneurons in lampreys, frogs, turtles and young rats, using light microscopic analysis of HRP- or neurobiotin-labeled motoneurons.