Neither increased nor decreased availability of cortical serotonin (5HT) disturbs barrel field formation in isocaloric undernourished rat pups

• Published in: International journal of developmental neuroscience 2002-10, Vol.20 (6), p.497-501
• Main Authors: Gutiérrez‐Ospina, Gabriel, Manjarrez‐Gutiérrez, Gabriel, González, Cesar, López, Sandra, Herrera, Rocı́o, Medina Aguirre, Ivett, Hernández‐R, Jorge
• Format: Article
• Language: English
• Subjects: Afferent Pathways - drug effects; Afferent Pathways - growth & development; Afferent Pathways - metabolism; Animals; Animals, Newborn; Barrels; Body Patterning - drug effects; Body Patterning - physiology; Body Weight - drug effects; Body Weight - physiology; Cell Differentiation - drug effects; Cell Differentiation - physiology; Developmental timing; Fenclonine - pharmacology; Food Deprivation - physiology; Neurotrophic factors; Primary somatosensory cortex; Raphe Nuclei - drug effects; Raphe Nuclei - growth & development; Raphe Nuclei - metabolism; Rats; Rats, Wistar; Serotonin; Serotonin - deficiency; Serotonin Antagonists - pharmacology; Somatosensory Cortex - drug effects; Somatosensory Cortex - growth & development; Somatosensory Cortex - metabolism; Undernutrition; Vibrissae - innervation; Vibrissae - physiology
• ISSN: 0736-5748; 1873-474X
• DOI: 10.1016/S0736-5748(02)00058-8

Serotonin (5HT) is expressed transiently in primary sensory areas of the rat neocortex during the establishment of the thalamo‐cortical topography and somatotopy. The precise role of 5HT during the specification of neocortical areas is still uncertain. We evaluated the effects of increasing and decreasing cortical serotonin concentrations on the specification of the barrel cortex using a rat model of isocaloric undernutrition. This manipulation increases brain 5HT levels during brain development. Undernourished animals were also treated with p‐clorophenylalanine; an inhibitor of 5HT synthesis. Barrels representing the head were readily seen at postnatal day 5 in control and p‐clorophenylalanine treated rats. In contrast, undernourished rats treated or not with p‐clorophenylalanine showed no barrels representing the head but until postnatal day 7. Chromatographic analyses demonstrated that the concentration of cortical 5HT increased by 50% in undernourished pups during barrel field formation. Control and undernourished animals treated with p‐clorophenylalanine had a significant reduction (90%) of 5HT in the cortex. The overall geometry of the barrel field and of individual barrels was similar among animal groups. Our results support that 5HT plays a small role in triggering and timing barrel field somatotopy.