PMID- 8847634
OWN - NLM
STAT- MEDLINE
DCOM- 19961023
LR  - 20190512
IS  - 0022-3751 (Print)
IS  - 1469-7793 (Electronic)
IS  - 0022-3751 (Linking)
VI  - 489 ( Pt 2)
IP  - Pt 2
DP  - 1995 Dec 1
TI  - Distinct omega-agatoxin-sensitive calcium currents in somata and axon terminals 
      of rat supraoptic neurones.
PG  - 383-8
AB  - 1. Voltage-dependent calcium currents were measured at room temperature using 
      whole-cell patch clamp in acutely isolated somata and axon terminals of the 
      magnocellular neurosecretory cells (MNCs) from the rat supraoptic nucleus. 2. 
      Administration of omega-agatoxin IVA (omega-Aga IVA) blocked a high-threshold 
      non-inactivating current. This current has an IC50 for omega-Aga IVA of 3 nM; no 
      other types of currents were blocked at doses of up to 500 nM. 3. In the axon 
      terminals omega-Aga IVA blocked a high-threshold current that inactivates 
      markedly (tau approximately 448 ms), and has a much lower sensitivity to the 
      toxin, with an IC50 of 270 nM. Unlike the somatic current, the effect of 
      omega-Aga IVA in the terminals is largely prevented by omega-conotoxin GVIA 
      (omega-CgTX). 4. These data suggest that MNC somata express a single type of 
      omega-Aga IVA-sensitive calcium current similar to the P-type calcium current 
      described in other cells. However, the omega-Aga IVA-sensitive current in axon 
      terminals differs from both the P-type and the recently identified Q-type current 
      in that it is also sensitive to omega-CgTX. The distinct biophysical properties 
      of the currents in somata and axon terminals may have important physiological 
      implications.
FAU - Fisher, T E
AU  - Fisher TE
AD  - Centre for Research in Neuroscience, McGill University, Montreal, Quebec, Canada.
FAU - Bourque, C W
AU  - Bourque CW
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - J Physiol
JT  - The Journal of physiology
JID - 0266262
RN  - 0 (Calcium Channel Blockers)
RN  - 0 (Calcium Channels)
RN  - 0 (Spider Venoms)
RN  - 0 (omega-Agatoxin IVA)
SB  - IM
MH  - Animals
MH  - Axons/drug effects/*physiology
MH  - Calcium Channel Blockers/*pharmacology
MH  - Calcium Channels/*drug effects/*physiology
MH  - Dose-Response Relationship, Drug
MH  - Male
MH  - Patch-Clamp Techniques
MH  - Rats
MH  - Spider Venoms/*pharmacology
MH  - Supraoptic Nucleus/drug effects/*physiology
MH  - Time Factors
MH  - omega-Agatoxin IVA
PMC - PMC1156766
EDAT- 1995/12/01 00:00
MHDA- 1995/12/01 00:01
PMCR- 1995/12/01
CRDT- 1995/12/01 00:00
PHST- 1995/12/01 00:00 [pubmed]
PHST- 1995/12/01 00:01 [medline]
PHST- 1995/12/01 00:00 [entrez]
PHST- 1995/12/01 00:00 [pmc-release]
AID - 10.1113/jphysiol.1995.sp021059 [doi]
PST - ppublish
SO  - J Physiol. 1995 Dec 1;489 ( Pt 2)(Pt 2):383-8. doi: 
      10.1113/jphysiol.1995.sp021059.