PMID- 7859089
OWN - NLM
STAT- MEDLINE
DCOM- 19950322
LR  - 20190614
IS  - 0006-8993 (Print)
IS  - 0006-8993 (Linking)
VI  - 662
IP  - 1-2
DP  - 1994 Oct 31
TI  - Spontaneous activity of first- and second-order neurons in the frog olfactory 
      system.
PG  - 31-44
AB  - The spontaneous activity of first-order neurons (neuroreceptors of the mucosa) 
      and second-order neurons (mitral cells of the bulb) was recorded extracellularly 
      in the frog olfactory system. To assess the influence of peripheral inputs upon 
      mitral cells, the bulb was either normally connected or partially deafferented. 
      Our first set of findings concern the firing behavior. We found that most neurons 
      generated interspike intervals (ISIs) that were stationary in mean and variance, 
      and were not serially correlated at first and second order. Individual spikes in 
      mitral cells and bursts of spikes in neuroreceptors were found to be generated by 
      a Poisson process. Stochastic modeling suggests that the Poissonian behavior 
      depends on the mean value of the membrane potential at the axon hillock. In these 
      models, the mean potential in mitral cells would be far below the firing 
      threshold and in neuroreceptors it would fluctuate at random between two states, 
      one close to resting potential (between bursts) and the other close to the firing 
      threshold with occasional crossings (within bursts). Secondly, partially 
      deafferented mitral cells had significantly higher activity and lower variance 
      than mitral cells receiving normal afferent input. This effect gives evidence 
      that peripheral inputs influence mitral cells at rest not only through direct 
      excitation but also through indirect inhibition exerted by local neurons. Thus, 
      the unstimulated state of the olfactory bulb would not be qualitatively different 
      from its stimulated state in the sense that both states involve the same types of 
      synaptic interactions. Consequently, understanding the synaptic relationships 
      that take place in the bulb network can benefit from studies of its spontaneous 
      activity.
FAU - Rospars, J P
AU  - Rospars JP
AD  - Laboratoire de Biometrie, Institut National de la Recherche Agronomique, 
      Versailles, France.
FAU - Lansky, P
AU  - Lansky P
FAU - Vaillant, J
AU  - Vaillant J
FAU - Duchamp-Viret, P
AU  - Duchamp-Viret P
FAU - Duchamp, A
AU  - Duchamp A
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Netherlands
TA  - Brain Res
JT  - Brain research
JID - 0045503
SB  - IM
MH  - Action Potentials/physiology
MH  - Animals
MH  - Chemoreceptor Cells/physiology
MH  - Electrophysiology
MH  - In Vitro Techniques
MH  - Models, Neurological
MH  - Neurons, Afferent/*physiology
MH  - Olfactory Bulb/cytology/physiology
MH  - Olfactory Mucosa/innervation
MH  - Olfactory Pathways/cytology/*physiology
MH  - Poisson Distribution
MH  - Rana ridibunda
MH  - Regression Analysis
MH  - Smell/*physiology
EDAT- 1994/10/31 00:00
MHDA- 1994/10/31 00:01
CRDT- 1994/10/31 00:00
PHST- 1994/10/31 00:00 [pubmed]
PHST- 1994/10/31 00:01 [medline]
PHST- 1994/10/31 00:00 [entrez]
AID - 0006-8993(94)90793-5 [pii]
AID - 10.1016/0006-8993(94)90793-5 [doi]
PST - ppublish
SO  - Brain Res. 1994 Oct 31;662(1-2):31-44. doi: 10.1016/0006-8993(94)90793-5.