Transient Uptake and Storage of Serotonin in Developing Thalamic Neurons

• Published in: Neuron (Cambridge, Mass.) Mass.), 1996-11, Vol.17 (5), p.823-835
• Main Authors: Lebrand, Cécile, Cases, Olivier, Adelbrecht, Christine, Doye, Anne, Alvarez, Chantal, El Mestikawy, Salah, Seif, Isabelle, Gaspar, Patricia
• Format: Article
• Language: English
• Subjects: Age Factors; Animals; Antibody Specificity; Biological Transport - physiology; Carrier Proteins - analysis; Carrier Proteins - genetics; Carrier Proteins - metabolism; Cerebral Cortex - cytology; Cerebral Cortex - metabolism; Gene Expression - physiology; Immunohistochemistry; In Situ Hybridization; Membrane Glycoproteins - analysis; Membrane Glycoproteins - genetics; Membrane Glycoproteins - metabolism; Membrane Transport Proteins; Mice; Mice, Inbred C57BL; Nerve Tissue Proteins; Neurons, Afferent - chemistry; Neurons, Afferent - metabolism; Neuropeptides; Neurotransmitter Agents - analysis; Neurotransmitter Agents - genetics; Neurotransmitter Agents - metabolism; Rats; Rats, Sprague-Dawley; RNA, Messenger - analysis; Serotonin - biosynthesis; Serotonin - immunology; Serotonin - pharmacokinetics; Serotonin Plasma Membrane Transport Proteins; Synaptic Vesicles - metabolism; Thalamus - cytology; Thalamus - growth & development; Thalamus - metabolism; Time Factors; Tritium; Vesicular Biogenic Amine Transport Proteins; Vesicular Monoamine Transport Proteins
• ISSN: 0896-6273; 1097-4199
• DOI: 10.1016/S0896-6273(00)80215-9

Serotonin (5-HT) has been shown to affect the development and patterning of the mouse barrelfield. We show that the dense transient 5-HT innervation of the somatosensory, visual, and auditory cortices originates in the thalamus rather than in the raphe: 5-HT is detected in thalamocortical fibers and most 5-HT cortical labeling disappears after thalamic lesions. Thalamic neurons do not synthesize 5-HT but take up exogenous 5-HT through 5-HT high affinity uptake sites located on thalamocortical axons and terminals. 3H–5-HT injected into the cortex is retrogradely transported to thalamic neurons. In situ hybridization shows a transient expression of the genes encoding the serotonin transporter and the vesicular monoamine transporter in thalamic sensory neurons. In these glutamatergic neurons, internalized 5-HT might thus be stored and used as a “borrowed transmitter” for extraneuronal signaling or could exert an intraneuronal control on thalamic maturation.