Barrel pattern formation requires serotonin uptake by thalamocortical afferents, and not vesicular monoamine release.
نویسندگان
چکیده
Thalamocortical neurons innervating the barrel cortex in neonatal rodents transiently store serotonin (5-HT) in synaptic vesicles by expressing the plasma membrane serotonin transporter (5-HTT) and the vesicular monoamine transporter (VMAT2). 5-HTT knock-out (ko) mice reveal a nearly complete absence of 5-HT in the cerebral cortex by immunohistochemistry, and of barrels, both at P7 and adulthood. Quantitative electron microscopy reveals that 5-HTT ko affects neither the density of synapses nor the length of synaptic contacts in layer IV. VMAT2 ko mice, completely lacking activity-dependent vesicular release of monoamines including 5-HT, also show a complete lack of 5-HT in the cortex but display largely normal barrel fields, despite sometimes markedly reduced postnatal growth. Transient 5-HTT expression is thus required for barrel pattern formation, whereas activity-dependent vesicular 5-HT release is not.
منابع مشابه
Effects of elevated serotonin levels on patterns of GAP-43 expression during barrel development in rat somatosensory cortex.
Elevating cortical serotonin (5-HT) in rats with clorgyline, a monoamine oxidase A (MAO(A)) inhibitor, from postnatal day (P-0) to P-6 delays the organization of thalamocortical afferent fibers into a vibrissae-related pattern in the somatosensory cortex (S-I). Despite continued elevation of cortical 5-HT through P-8, the thalamocortical fibers do form, albeit with some delay, a characteristic ...
متن کاملSpecific and Non-Specific Thalamocortical Afferents to the Whisker–Related Sensory Cortical Region in Rats with Congenital Hypothyroidism
Background & Aims: Thyroid hormones are of great importance in the development of the central nervous system. Congenital hypothyroidism may affect the reorganization of specific and non-specific thalamocortical afferents to whisker–related sensory (wS1) corticol region in rats. Methods: Congenital hypothyroidism was induced by adding propylthiouracil (PTU) (25 ppm) to the rats...
متن کاملDissociating barrel development and lesion-induced plasticity in the mouse somatosensory cortex.
In the mouse somatosensory cortex, thalamocortical axons (TCAs) corresponding to individual whiskers cluster into restricted barrel domains during the first days of life. If whiskers are lesioned before that time, the cortical space devoted to the afferents from the damaged whisker shrinks and becomes occupied by thalamocortical afferents from neighboring unlesioned whiskers. This plasticity en...
متن کاملLack of Barrels in the Somatosensory Cortex of Monoamine Oxidase A–Deficient Mice: Role of a Serotonin Excess during the Critical Period
In a transgenic mouse line (Tg8) deficient for the gene encoding monoamine oxidase A (MAOA), we show that the primary somatosensory cortex (S1) lacks the characteristic barrel-like clustering of layer IV neurons, whereas normal pattern formation exists in the thalamus and the trigeminal nuclei. No barrel-like patterns were visible with tenascin or serotonin immunostaining or with labeling of th...
متن کاملTransient Uptake and Storage of Serotonin in Developing Thalamic Neurons
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 synthesiz...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- The Journal of neuroscience : the official journal of the Society for Neuroscience
دوره 21 17 شماره
صفحات -
تاریخ انتشار 2001