[Laminar distribution of the active spinal cord neurons during the feeding-related stereotyped movements in the rat].

The comparative study of expression of early c-fos-gene (marker of neuronal activation) and NADPH-diaphorase reactivity (NADPH-dr) was performed in the cervical spinal cord of rats in the control (intact) animal, in the state of starvation and after realization of long-lasting (repeated 4 to 12 times per minute for 30 min) motivated stereotyped food-procuring forelimb movements. In comparison with control rats; in the starving rats or rats showed forelimb movement to reach-to-grasp the food, the number of Fos-immunoreactive (Fos-ir) cells in the dorsal and ventral horns of a 40-microm-thick slice was significantly greater (P < 0.05). The number of Fosir neurons in the starving state clearly exceeded that in the most layers after realization of movements. Increase of Fos immunoreactivity in the superficial (2i, 3) and deeper (4, 5) layers of the dorsal horn was initiated, evidently, by signals from peripheral and supraspinal structures. We also found labelled cells within layers 6-8, and 9 demonstrating the activity of interneurons and motoneurons directly involved into generation of operant forelimb movements. According to our data, high density of NADPH-dr/NO-generating neurons in the C6/C7 segments are observed in the substance gelatinosa (layer 2i) and layers 7 and 10. NADPH-dr cells and Fos-ir neurons were intermixed within the layers but did not demonstrate double-labelling. It is possible to suggest that NADPH-dr/NO-generating cells of the spinal cord did not operate under realization of the studied operant reflexes, which did not include nociceptive component.

[NADPH-diaphorase neurons and their interrelationship with microvascular vessels in the basal forebrain limbic structures and hypothalamus].

NADPH-diaphorase histochemistry was used to study the distribution and density of labeled neurons in the limbic structures and hypothalamus in intact rat. NADPH-diaphorase positive neurons were registered in the basal forebrain-medial septal nucleus (MS), the nuclei of the diagonal band of Broca (VDB, HDB), substancia innominata (SI) and the nucleus basalis of Meynert (B). These areas largely overlap with the cholinergic CH1-CH4 forebrain system of the rodent brain. The order of density of labeled neurons in different regions of the basal forebrain was as following sequence: HDB > VDB > SI > B. The highest densities of the reactive neurons (> 1000 labeled neurons per section 200x200 microm2) was found in the islands of Calleja (ICjs). In the supraoptic (SO) and paraventricular (Pa) nuclei of hypothalamus were recorded > 130 and > 100 labeled units, respectively. The lowest density of labeled neurons was recorded within the SI-B complex: < 10 reactive units. Reactive neurons, their dendrites and axon-like processes within the ICjs, SO, Pa, the lateral nucleus hypothalamus (LH) often surround arterioles which traverse the structures. We suggest that NADPH-diaphorase-reactive (NO-generating) neurons within the ICjs and hypothalamus are involved in regulation of the regional, blood flow (RBF) that is important to adapt the blood flow to changes in neuronal activity of the basal forebrain structures.