UI  - 96426271
AU  - Habbicht H
AU  - Vater M
TI  - A microiontophoretic study of acetylcholine effects in the inferior
      colliculus of horseshoe bats: implications for a modulatory role.
LA  - Eng
MH  - Acetylcholine/administration & dosage/*pharmacology
MH  - Acoustic Stimulation
MH  - Action Potentials/physiology
MH  - Animal
MH  - Chiroptera/*physiology
MH  - Evoked Potentials, Auditory/drug effects
MH  - Female
MH  - Inferior Colliculus/*physiology
MH  - Iontophoresis
MH  - Muscarinic Agonists/pharmacology
MH  - Muscarinic Antagonists/pharmacology
MH  - Nicotinic Agonists/pharmacology
MH  - Nicotinic Antagonists/pharmacology
MH  - Receptors, Presynaptic/drug effects/physiology
MH  - Support, Non-U.S. Gov't
RN  - 0 (Muscarinic Agonists)
RN  - 0 (Muscarinic Antagonists)
RN  - 0 (Nicotinic Agonists)
RN  - 0 (Nicotinic Antagonists)
RN  - 0 (Receptors, Presynaptic)
RN  - 51-84-3 (Acetylcholine)
PT  - JOURNAL ARTICLE
DA  - 19961226
DP  - 1996 Jun 17
IS  - 0006-8993
TA  - Brain Res
PG  - 169-79
SB  - M
CY  - NETHERLANDS
IP  - 2
VI  - 724
JC  - B5L
AA  - Author
EM  - 199702
AB  - The effects of acetylcholine (ACh) in processing acoustical information
      in the inferior colliculus (IC) of awake horseshoe bats (Rhinolophus
      rouxi) were examined with single cell recordings and
      microiontophoresis. Cholinergic agonists, acetylcholine and carbachol
      raised the stimulus evoked discharge in 37% and suppressed responses in
      16% of the sample. They did not alter the shapes of tuning curves and
      rate-intensity functions but the latter showed parallel shifting. The
      nicotinic antagonist, hexamethonium raised neuronal activity in 52% of
      neurons without affecting discharge patterns. The nonspecific
      muscarinic antagonist atropine was mostly inhibitory (62% of units) and
      caused changes in temporal discharge patterns by affecting the tonic
      response component. The selective muscarinic ml antagonist pirenzepine,
      also had an inhibitory effect (37% of units) and predominantly
      influenced the tonic response component. The selective m2 antagonist,
      gallamine however produced mainly excitatory effects (64% of units) and
      changed temporal discharge patterns by adding tonic response
      components. These findings may indicate a differential pre- and
      postsynaptic synaptic distribution of m1/m2 receptors in the inferior
      colliculus as reported for other brain structures. The results indicate
      that ACh plays a neuromodulatory transmitter role in the auditory
      midbrain by setting the level of neuronal activity. Its exact function
      in particular behavioral contexts remains to be determined, since the
      origin of cholinergic innervation of the mammalian IC is still unclear.
AD  - Institut fur Zoologie, Universitat Regensburg, Germany.
PMID- 0008828565
SO  - Brain Res 1996 Jun 17;724(2):169-79

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