PMID- 19057002
OWN - NLM
STAT- MEDLINE
DCOM- 20090312
LR  - 20141120
IS  - 8750-7587 (Print)
IS  - 0161-7567 (Linking)
VI  - 106
IP  - 2
DP  - 2009 Feb
TI  - Differential modulation of cerebellar climbing fiber and parallel fiber synaptic 
      responses at high pressure.
PG  - 729-36
LID - 10.1152/japplphysiol.90853.2008 [doi]
AB  - High pressure, which induces central nervous system (CNS) dysfunction 
      (high-pressure neurological syndrome) depresses synaptic transmission at all 
      synapses examined to date. Several lines of evidence indicate an inhibitory 
      effect of pressure on Ca(2+) entry into the presynaptic terminal. In the present 
      work we studied for the first time the effect of pressure on the cerebellar 
      climbing fiber (CF) synaptic responses. Pressure modulation of cerebellar 
      synaptic plasticity was tested in both the CF and parallel fiber (PF) pathways 
      using paired-pulse protocols. CF synapses, which normally operate at a high 
      baseline release probability, demonstrate paired-pulse depression (PPD). High 
      pressure reduced CF synaptic responses at 5.1 and 10.1 MPa but did not affect its 
      PPD. High extracellular Ca(2+) concentration ([Ca(2+)](o)) could not antagonize 
      the effect of pressure on the CF response, whereas low [Ca(2+)](o), in contrast 
      to pressure, decreased both the response amplitude and the observed PPD. PF 
      synapses, which usually operate at low release probability, exhibit paired-pulse 
      facilitation (PPF). Pressure increased PF PPF at all interstimulus intervals 
      (ISIs) tested (20-200 ms). Several Ca(2+) channel blockers as well as low 
      [Ca(2+)](o) could mimic the effect of pressure on the PF response but 
      significantly increased the PPF only at the 20-ms ISI. These results, together 
      with previous data, show that the CF synapse is relatively resistant to pressure. 
      The lack of pressure effect on CF PPD is surprising and may suggest that the PPD 
      is not directly linked to synaptic depletion, as generally suggested. The 
      increase in PPF of the PF at pressure, which is mimicked by Ca(2+) channel 
      blockers or low [Ca(2+)](o), further supports pressure involvement in synaptic 
      release mechanism(s). These results also indicate that pressure effects may be 
      selective for various types of synapses in the CNS.
FAU - Etzion, Yoram
AU  - Etzion Y
AD  - Department of Physiology, Zlotowski Center for Neuroscience, Ben-Gurion 
      University of the Negev, Beer-Sheva, 84105, Israel.
FAU - Mor, Amir
AU  - Mor A
FAU - Grossman, Yoram
AU  - Grossman Y
LA  - eng
PT  - Comparative Study
PT  - Journal Article
DEP - 20081204
PL  - United States
TA  - J Appl Physiol (1985)
JT  - Journal of applied physiology (Bethesda, Md. : 1985)
JID - 8502536
RN  - 0 (Calcium Channel Blockers)
RN  - SY7Q814VUP (Calcium)
SB  - IM
MH  - Animals
MH  - Calcium/metabolism
MH  - Calcium Channel Blockers/pharmacology
MH  - Cerebellum/cytology/drug effects/*metabolism
MH  - Dendrites/metabolism
MH  - Electric Stimulation
MH  - Guinea Pigs
MH  - *Hyperbaric Oxygenation
MH  - In Vitro Techniques
MH  - Male
MH  - Nerve Fibers/drug effects/*metabolism
MH  - *Neuronal Plasticity/drug effects
MH  - Pressure
MH  - *Synaptic Transmission/drug effects
MH  - Time Factors
EDAT- 2008/12/06 09:00
MHDA- 2009/03/13 09:00
CRDT- 2008/12/06 09:00
PHST- 2008/12/06 09:00 [pubmed]
PHST- 2009/03/13 09:00 [medline]
PHST- 2008/12/06 09:00 [entrez]
AID - 90853.2008 [pii]
AID - 10.1152/japplphysiol.90853.2008 [doi]
PST - ppublish
SO  - J Appl Physiol (1985). 2009 Feb;106(2):729-36. doi: 
      10.1152/japplphysiol.90853.2008. Epub 2008 Dec 4.