QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

HOME  |   SEARCH  |   ARCHIVE  |   SUBSCRIBE  |   CONTACT  |   HELP

This Article Full Text (PDF) Submit an eLetter Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (46) Citing Articles via Google Scholar Google Scholar Articles by Shumway, C. A. Search for Related Content PubMed PubMed Citation Articles by Shumway, C. A.

 Previous Article  |  Next Article 

Journal of Neuroscience, Vol 9, 4400-4415, Copyright © 1989 by Society for Neuroscience

ARTICLE

Multiple electrosensory maps in the medulla of weakly electric gymnotiform fish. II. Anatomical differences

CA Shumway
Neurobiology Unit, Scripps Institution of Oceanography, UCSD, La Jolla, California 92093.

Both wave- and pulse-type species of weakly electric gymnotiform fish have 3 topographic maps of electroreceptive information in the electrosensory lateral line lobe (ELL). These maps receive identical input from trifurcating axons of phase- and amplitude-coding primary afferents (Carr et al., 1982; Heiligenberg and Dye, 1982). Physiological experiments in the ELL of the wave-type fish Eigenmannia show that the amplitude-coding pyramidal cells differ among maps with respect to receptive field size, sensitivity, rate of adaptation, and temporal-frequency response (Shumway, 1989). This study investigated morphological correlates of the physiological differences among maps. Estimates of primary afferent convergence in Eigenmannia, based on map size, cell counts, and areas of terminal fields from intracellularly filled P-type primary afferents, suggest a 2-fold increase in convergence in the lateral map relative to the centromedial map. Similar differences in convergence between maps are found in the wave- type species Apteronotus leptorhynchus and the pulse-type fish Hypopomus occidentalis. The lateral and centrolateral maps in Hypopomus, however, show an even greater difference in convergence. Comparison of the efferent projections of pyramidal cells among the different maps of Eigenmannia indicates that cells from the 3 maps terminate in the same laminae of the torus semicircularis, but the maps differ in the strength of projection to particular laminae. In both wave-type species, the abundance of a class of interneurons which receives descending input and inhibits pyramidal cells (interneurons of the ventral molecular layer) differs among maps; the centromedial map has 10 times fewer neurons of this type than the other 2 maps. Cytochrome oxidase studies in all 3 species demonstrated increased levels of activity in the lateral map, within the region receiving descending input from the cerebellum. These results suggest that the primary anatomical bases of the physiological differences among maps are differences in the amount of primary afferent convergence, coupled with differences in descending input.

This article has been cited by other articles:

				R. Krahe, J. Bastian, and M. J. Chacron Temporal Processing Across Multiple Topographic Maps in the Electrosensory System J Neurophysiol, August 1, 2008; 100(2): 852 - 867. [Abstract] [Full Text] [PDF]

				J. Bastian, M. J. Chacron, and L. Maler Receptive Field Organization Determines Pyramidal Cell Stimulus-Encoding Capability and Spatial Stimulus Selectivity J. Neurosci., June 1, 2002; 22(11): 4577 - 4590. [Abstract] [Full Text] [PDF]

				R. Krahe, G. Kreiman, F. Gabbiani, C. Koch, and W. Metzner Stimulus Encoding and Feature Extraction by Multiple Sensory Neurons J. Neurosci., March 15, 2002; 22(6): 2374 - 2382. [Abstract] [Full Text] [PDF]

				J. E. Lewis and L. Maler Neuronal Population Codes and the Perception of Object Distance in Weakly Electric Fish J. Neurosci., April 15, 2001; 21(8): 2842 - 2850. [Abstract] [Full Text] [PDF]

				M. Castello, P. Aguilera, O Trujillo-Cenoz, and A. Caputi Electroreception in Gymnotus carapo: pre-receptor processing and the distribution of electroreceptor types J. Exp. Biol., January 11, 2000; 203(21): 3279 - 3287. [Abstract] [PDF]

				M. Nelson and M. Maciver Prey capture in the weakly electric fish Apteronotus albifrons: sensory acquisition strategies and electrosensory consequences J. Exp. Biol., January 5, 1999; 202(10): 1195 - 1203. [Abstract] [PDF]

				N. Berman and L Maler Neural architecture of the electrosensory lateral line lobe: adaptations for coincidence detection, a sensory searchlight and frequency-dependent adaptive filtering J. Exp. Biol., January 5, 1999; 202(10): 1243 - 1253. [Abstract] [PDF]

				R. Dunn, D Bottai, and L Maler Molecular biology of the apteronotus NMDA receptor NR1 subunit J. Exp. Biol., January 5, 1999; 202(10): 1319 - 1326. [Abstract] [PDF]

				W Metzner Neural circuitry for communication and jamming avoidance in gymnotiform electric fish J. Exp. Biol., January 5, 1999; 202(10): 1365 - 1375. [Abstract] [PDF]

				N. J. Berman and L. Maler Inhibition Evoked From Primary Afferents in the Electrosensory Lateral Line Lobe of the Weakly Electric Fish (Apteronotus leptorhynchus) J Neurophysiol, December 1, 1998; 80(6): 3173 - 3196. [Abstract] [Full Text] [PDF]

				M. Kawasaki and Y.-X. Guo Parallel Projection of Amplitude and Phase Information from the Hindbrain to the Midbrain of the African Electric Fish Gymnarchus niloticus J. Neurosci., September 15, 1998; 18(18): 7599 - 7611. [Abstract] [Full Text] [PDF]

Home  |   Search  |   Archive  |   Subscribe  |   Contact  |   Help