Chem. Senses 28: 181-189,
2003
© Oxford University Press 2003
Sensitivity and Selectivity of Neurons in the Medial Region of the Olfactory Bulb to Skin Extract from Conspecifics in Crucian Carp, Carassius carassius
Division of General Physiology, Department of Biology, PO Box 1051, University of Oslo, N-0316 Oslo, Norway
Correspondence to be sent to: Kjell B. Døving, Division of General Physiology, Department of Biology, PO Box 1051, University of Oslo, N-0316 Oslo, Norway. e-mail: kjelld{at}bio.uio.no
To examine the functional subdivision of the teleost olfactory bulb,
extracellular recordings were made from the posterior part of the medial
region of the olfactory bulb in the crucian carp, Carassius
carassius. Bulbar units classified as type I or type II were frequently
and simultaneously encountered at a recording site. Type I units displayed a
diphasic action potential (AP) with a relatively small amplitude, a short
duration (rise time 
1 ms) and high spontaneous activity (2.5 per s). Type
II units exhibited an AP with a rise time of 1.8 ms and low spontaneous
activity (1.5 per s). The AP of this latter unit was nearly always followed by
a slow potential, a characteristic diphasic wave with a rise time of 5
ms. Chemical stimulation of the olfactory organ with a graded series of
conspecific skin extract induced an increased firing of the type I units.
During the period of increased activity of the type I units, the activity of
the type II units was suppressed. Stimulation with nucleotides, amino acids
and taurolithocholic acid did not induce firing of the type I units of the
posterior part of the medial region of the olfactory bulb. These results
indicate that the posterior part of the medial region of the olfactory bulb is
both sensitive to and selective for skin extract from conspecifics, which has
been shown to be a potent stimulus inducing alarm behaviour. The results of
the present study indicate that recording single unit activity from a
particular region of the olfactory bulb is a suitable method for isolating
pheromones or other chemical signals that induce specific activity in the
olfactory system. The projection of the neurons categorized as type II was
determined by antidromic activation of their axons by electrical stimulation
applied to the medial bundle of the medial olfactory tract. The anatomical
basis of the type I and type II units in the fish olfactory bulb is
discussed.
Key words: bulbar neurons, mitral cells, olfactory bulb, ruffed cells, selectivity, sensitivity, skin extract
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  E. H. Hamdani and K. B. Doving Specific Projection of the Sensory Crypt Cells in the Olfactory System in Crucian Carp, Carassius carassius Chem Senses, January 1, 2006; 31(1): 63 - 67. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Lastein, E. H. Hamdani, and K. B. Doving Gender Distinction in Neural Discrimination of Sex Pheromones in the Olfactory Bulb of Crucian Carp, Carassius carassius Chem Senses, January 1, 2006; 31(1): 69 - 77. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. A. Nikonov, T. E. Finger, and J. Caprio Beyond the olfactory bulb: An odotopic map in the forebrain PNAS, December 20, 2005; 102(51): 18688 - 18693. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. A. Nikonov and J. Caprio Odorant Specificity of Single Olfactory Bulb Neurons to Amino Acids in the Channel Catfish J Neurophysiol, July 1, 2004; 92(1): 123 - 134. [Abstract] [Full Text] [PDF]
|
|