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Auditory thalamocortical synaptic transmission in vitro.
- Source :
-
Journal of neurophysiology [J Neurophysiol] 2002 Jan; Vol. 87 (1), pp. 361-84. - Publication Year :
- 2002
-
Abstract
- To facilitate an understanding of auditory thalamocortical mechanisms, we have developed a mouse brain-slice preparation with a functional connection between the ventral division of the medial geniculate (MGv) and the primary auditory cortex (ACx). Here we present the basic characteristics of the slice in terms of physiology (intracellular and extracellular recordings, including current source density analysis), pharmacology (including glutamate receptor involvement), and anatomy (gross anatomy, Nissl, parvalbumin immunocytochemistry, and tract tracing with 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate). Thalamocortical transmission in this preparation (the "primary" slice) involves both alpha-amino-3-hydroxy-5-methylisoxazole-4-proprionic acid/kainate and N-methyl-D-aspartate-type glutamate receptors that appear to mediate monosynaptic inputs to layers 3-4 of ACx. MGv stimulation also initiates disynaptic inhibitory postsynaptic potentials and longer-duration intracortical, polysynaptic activity. Important differences between responses elicited by MGv versus conventional columnar ("on-beam") stimulation emphasize the necessity of thalamic activation to infer thalamocortical mechanisms. We also introduce a second slice preparation, the "shell" slice, obtained from the brain region immediately ventral to the primary slice, that may contain a nonprimary thalamocortical pathway to temporal cortex. In the shell slice, stimulation of the thalamus or the region immediately ventral to it appears to produce fast activation of synapses in cortical layer 1 followed by robust intracortical polysynaptic activity. The layer 1 responses may result from orthodromic activation of nonprimary thalamocortical pathways; however, a plausible alternative could involve antidromic activation of corticotectal neurons and their layer 1 collaterals. The primary and shell slices will provide useful tools to investigate mechanisms of information processing in the ACx.
- Subjects :
- Action Potentials physiology
Animals
Auditory Cortex anatomy & histology
Auditory Cortex drug effects
Auditory Pathways anatomy & histology
Auditory Pathways drug effects
Calcium metabolism
Calcium pharmacology
Electric Stimulation
Excitatory Amino Acid Antagonists pharmacology
Excitatory Postsynaptic Potentials drug effects
Excitatory Postsynaptic Potentials physiology
Fluorescent Dyes
Geniculate Bodies anatomy & histology
Geniculate Bodies drug effects
Geniculate Bodies physiology
In Vitro Techniques
Mice
Mice, Inbred Strains
Neural Inhibition physiology
Reaction Time physiology
Receptors, AMPA antagonists & inhibitors
Receptors, N-Methyl-D-Aspartate antagonists & inhibitors
Synaptic Transmission drug effects
Thalamus anatomy & histology
Thalamus drug effects
Auditory Cortex physiology
Auditory Pathways physiology
Synaptic Transmission physiology
Thalamus physiology
Subjects
Details
- Language :
- English
- ISSN :
- 0022-3077
- Volume :
- 87
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Journal of neurophysiology
- Publication Type :
- Academic Journal
- Accession number :
- 11784756
- Full Text :
- https://doi.org/10.1152/jn.00549.2001