Abstract
The ventral posterior nucleus of the thalamus (VP) receives two major sets of excitatory inputs, one from the ascending somatosensory pathways originating in the dorsal horn, dorsal column nuclei, and trigeminal nuclei, and the other originating from the cerebral cortex. Both systems use glutamate as neurotransmitter, as do the thalamocortical axons relaying somatosensory information from the VP to the primary somatosensory cortex (SI). The synapses formed by these projection systems differ anatomically, physiologically, and in their capacity for short-term synaptic plasticity. Glutamate uptake into synaptic vesicles and its release at central synapses depend on two isoforms of vesicular glutamate transporters, VGluT1 and VGluT2. Despite ample evidence of their complementary distribution, some instances exist of co-localization in the same brain areas or at the same synapses. In the thalamus, the two transcripts coexist in cells of the VP and other nuclei but not in the posterior or intralaminar nuclei. We show that the two isoforms are completely segregated at VP synapses, despite their widespread expression throughout the dorsal and ventral thalamus. We present immunocytochemical, ultrastructural, gene expression, and connectional evidence that VGluT1 in the VP is only found at corticothalamic synapses, whereas VGluT2 is only found at terminals made by axons originating in the spinal cord and brainstem. By contrast, the two VGluT isoforms are co-localized in thalamocortical axon terminals targeting layer IV, but not in those targeting layer I, suggesting the presence of two distinct projection systems related to the core/matrix pattern of organization of thalamocortical connectivity described in other mammals.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1258-1276 |
| Number of pages | 19 |
| Journal | Journal of Comparative Neurology |
| Volume | 507 |
| Issue number | 2 |
| DOIs | |
| State | Published - Mar 10 2008 |
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Keywords
- BNPI
- Core-matrix
- Corticothalamic
- DNPI
- Medial lemniscus
- Spinothalamic
- Synapses
ASJC Scopus subject areas
- Neuroscience(all)
Cite this
Vesicular glutamate transporters define two sets of glutamatergic afferents to the somatosensory thalamus and two thalamocortical projections in the mouse. / Graziano, Alessandro; Liu, Xiao Bo; Murray, Karl D; Jones, Edward G.
In: Journal of Comparative Neurology, Vol. 507, No. 2, 10.03.2008, p. 1258-1276.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Vesicular glutamate transporters define two sets of glutamatergic afferents to the somatosensory thalamus and two thalamocortical projections in the mouse
AU - Graziano, Alessandro
AU - Liu, Xiao Bo
AU - Murray, Karl D
AU - Jones, Edward G.
PY - 2008/3/10
Y1 - 2008/3/10
N2 - The ventral posterior nucleus of the thalamus (VP) receives two major sets of excitatory inputs, one from the ascending somatosensory pathways originating in the dorsal horn, dorsal column nuclei, and trigeminal nuclei, and the other originating from the cerebral cortex. Both systems use glutamate as neurotransmitter, as do the thalamocortical axons relaying somatosensory information from the VP to the primary somatosensory cortex (SI). The synapses formed by these projection systems differ anatomically, physiologically, and in their capacity for short-term synaptic plasticity. Glutamate uptake into synaptic vesicles and its release at central synapses depend on two isoforms of vesicular glutamate transporters, VGluT1 and VGluT2. Despite ample evidence of their complementary distribution, some instances exist of co-localization in the same brain areas or at the same synapses. In the thalamus, the two transcripts coexist in cells of the VP and other nuclei but not in the posterior or intralaminar nuclei. We show that the two isoforms are completely segregated at VP synapses, despite their widespread expression throughout the dorsal and ventral thalamus. We present immunocytochemical, ultrastructural, gene expression, and connectional evidence that VGluT1 in the VP is only found at corticothalamic synapses, whereas VGluT2 is only found at terminals made by axons originating in the spinal cord and brainstem. By contrast, the two VGluT isoforms are co-localized in thalamocortical axon terminals targeting layer IV, but not in those targeting layer I, suggesting the presence of two distinct projection systems related to the core/matrix pattern of organization of thalamocortical connectivity described in other mammals.
AB - The ventral posterior nucleus of the thalamus (VP) receives two major sets of excitatory inputs, one from the ascending somatosensory pathways originating in the dorsal horn, dorsal column nuclei, and trigeminal nuclei, and the other originating from the cerebral cortex. Both systems use glutamate as neurotransmitter, as do the thalamocortical axons relaying somatosensory information from the VP to the primary somatosensory cortex (SI). The synapses formed by these projection systems differ anatomically, physiologically, and in their capacity for short-term synaptic plasticity. Glutamate uptake into synaptic vesicles and its release at central synapses depend on two isoforms of vesicular glutamate transporters, VGluT1 and VGluT2. Despite ample evidence of their complementary distribution, some instances exist of co-localization in the same brain areas or at the same synapses. In the thalamus, the two transcripts coexist in cells of the VP and other nuclei but not in the posterior or intralaminar nuclei. We show that the two isoforms are completely segregated at VP synapses, despite their widespread expression throughout the dorsal and ventral thalamus. We present immunocytochemical, ultrastructural, gene expression, and connectional evidence that VGluT1 in the VP is only found at corticothalamic synapses, whereas VGluT2 is only found at terminals made by axons originating in the spinal cord and brainstem. By contrast, the two VGluT isoforms are co-localized in thalamocortical axon terminals targeting layer IV, but not in those targeting layer I, suggesting the presence of two distinct projection systems related to the core/matrix pattern of organization of thalamocortical connectivity described in other mammals.
KW - BNPI
KW - Core-matrix
KW - Corticothalamic
KW - DNPI
KW - Medial lemniscus
KW - Spinothalamic
KW - Synapses
UR - http://www.scopus.com/inward/record.url?scp=39649083368&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=39649083368&partnerID=8YFLogxK
U2 - 10.1002/cne.21592
DO - 10.1002/cne.21592
M3 - Article
C2 - 18181146
AN - SCOPUS:39649083368
VL - 507
SP - 1258
EP - 1276
JO - Journal of Comparative Neurology
JF - Journal of Comparative Neurology
SN - 0021-9967
IS - 2
ER -