Mapping the Pattern of Essential Neuroendocrine Cells Related to Puberty and < b > < i > VA Opsin < /i > < /b > Expression Provides Further Insight in the Photoreceptive Regulation of the Brain-Pituitary-Gonadal Axis in Atlantic Salmon ( < b > < i > Salmo salar < /i > < /b > )

This study presents a comprehensive topographic mapping ofgnrh2,gnrh3,kisspeptin 2 (kiss2),gonadotropin-inhibiting hormone (gnih), andVA opsin using in situ hybridization on mature Atlantic salmon brains. Neurons positive forgnrh3 are expressed in the olfactory bulb and ventral telencephalon, whilegnrh2-positive neurons are located dorsally in the midbrain tegmentum. Gonadotropin-inhibiting hormone (Gnih)-expressing cell bodies are present in the ventral thalamus and extend caudally to the hypothalamus withkiss2-expressing cells appearing in a lateral position.VA opsin-positive cells are present in the telencephalon, the rostro-dorsal ring of the left habenula, the ventral thalamus, and the midbrain tegmentum. The results show no similar co-location as found in birds, hypothesizing that the photoreceptive modulation ofGnrh in salmon may interact through neuronal networks. The topography analyses of the essential neuroendocrine cells related to sexual maturation in the Atlantic salmon brain show that diencephalic (thalamus, hypothalamus) and midbrain (tegmentum) regions seem central for controlling sexual maturation.

Source: Brain, Behavior and Evolution - August 3, 2022 Category: Neurology Source Type: research