| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Anatomical Sciences and Neurobiology, University of Louisville, Louisville, KY, USA
2 Cell Biology and Anatomy, Louisianna Health Sciences Center, New Orleans, LA, USA
* To whom correspondence should be addressed. E-mail: martha.bickford{at}louisville.edu.
The lateral posterior nucleus (LPN) is innervated by two different morphological types of cortical terminals that originate from cortical layers V and VI. Here we describe two distinct types of excitatory postsynaptic potentials (EPSPs) that were recorded in the LPN following stimulation of corticothalamic fibers. These types of EPSPs differed in amplitude, latency, rise time, and response to increasing levels of stimulus intensity. The most frequently encountered EPSP, type I, displayed a longer latency and slower rise time than the less frequently encountered type II EPSP. Type I EPSPs also showed a graded increase in amplitude with increasing levels of stimulation while type II EPSPs showed an all-or-none response. In response to repetitive stimulation (0.5Hz-20Hz), type I EPSPs displayed frequency-dependent facilitation, whereas type II EPSPs displayed frequency-dependent depression. Further details of these distinct forms of short-term synaptic plasticity were explored using paired-pulse stimuli. Pharmacology experiments revealed that both NMDA and non-NMDA glutamate receptors are involved in corticothalamic synaptic transmission in the LPN, and contribute to both synaptic facilitation and depression. Taken together with the results of our previous anatomical studies, these results suggest that type I EPSPs arise from stimulation of layer VI afferents, while type II EPSPs arise from stimulation of layer V inputs. Moreover, type I and type II EPSPs in the LPN may be functionally similar to corticogeniculate and retinogeniculate EPSPs, respectively.
This article has been cited by other articles:
|
|
 |
|
  A. Groh, C. P. J. de Kock, V. C. Wimmer, B. Sakmann, and T. Kuner Driver or Coincidence Detector: Modal Switch of a Corticothalamic Giant Synapse Controlled by Spontaneous Activity and Short-Term Depression J. Neurosci., September 24, 2008; 28(39): 9652 - 9663. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. C. Lee and S. M. Sherman Synaptic Properties of Thalamic and Intracortical Inputs to Layer 4 of the First- and Higher-Order Cortical Areas in the Auditory and Somatosensory Systems J Neurophysiol, July 1, 2008; 100(1): 317 - 326. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. E. Landisman and B. W. Connors VPM and PoM Nuclei of the Rat Somatosensory Thalamus: Intrinsic Neuronal Properties and Corticothalamic Feedback Cereb Cortex, December 1, 2007; 17(12): 2853 - 2865. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. G. Sirota, H. A. Swadlow, and I. N. Beloozerova Three Channels of Corticothalamic Communication during Locomotion J. Neurosci., June 22, 2005; 25(25): 5915 - 5925. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
I. Reichova and S. M. Sherman Somatosensory Corticothalamic Projections: Distinguishing Drivers From Modulators J Neurophysiol, October 1, 2004; 92(4): 2185 - 2197. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
