Amphibian Brains

Wilhelmus JAJ Smeets, Vrije Universiteit, Amsterdam, The Netherlands
Agustín González, Universidad Complutense, Madrid, Spain

Published online: January 2006

DOI: 10.1038/npg.els.0004095

Amphibians mark the transition from an aquatic to a terrestrial lifestyle. From a phylogenetic point of view, amphibians are, therefore, considered of particular interest for a better understanding of evolutionary processes in brain organization of vertebrates.

Keywords: evolution; nervous system; adaptation; vocal behaviour; motor behaviour

Figure 1. Lateral views and transverse sections from rostral (a) to caudal (d) through the brain of the frog Rana perezi (left) and the urodele Pleurodeles waltl (right). The levels of the transverse sections are indicated and are taken through the telencephalon (a) diencephalon (b), mesencephalon (c) and rhombencephalon (d). They illustrate the major differences in shape and distribution of cell bodies, as noted for the different amphibian orders. They also show the position of important structures such as the striatum, posterior tubercle, torus semicircularis and midbrain tectum. Acc, nucleus accumbens; aol, area octavolateralis; C, central thalamic nucleus; DTh, dorsal thalamic nuclei; DB, diagonal band nucleus; Dp, dorsal pallidum; Ep, entopeduncular nucleus; Ip, interpeduncular nucleus; La, lateral thalamic nucleus, anterior division; Lp, lateral pallium; Ls, lateral septum; Mp, medial pallium; Ms, medial septum; Ols, oliva superior; P, posterior thalamic nucleus; PT, pretectal region; Ra, raphe nuclei; Rm, nucleus reticularis medius; Str, striatum; T, tectum mesencephali; tegm, tegmentum mesencephali; Tor, torus semicircularis; VH, ventral hypothalamic nucleus; VM, ventromedial thalamic nucleus; VTh, ventral thalamus; IV, nucleus nervi trochlearis; VIIm, nucleus motorius nervi facialis; VIIId, nucleus dorsalis nervi vestibulocochlearis; VIIIv, nucleus ventralis nervi vestibulocochlearis.
Figure 2. Basal ganglia connections in ancestral tetrapods. The putative connections of the dorsal (a) and ventral (b) striatopallidal systems in ancestral tetrapods can be inferred from a comparative analysis of the basal ganglia organization in extant tetrapods. A9, substantia nigra, pars compacta; A10, ventral tegmental area; Acc, nucleus accumbens; Amy, amygdala; cDTh, caudal dorsal thalamic nuclei; DP, dorsal pallidum; Hb, habenula; HYP, hypothalamus; Ilm, intralaminar midline nuclei; LC, locus coeruleus; LDT, laterodorsal tegmental nucleus; Mp, medial pallium; PPN, pedunculopontine nucleus; PT, pretectal region; rDTh, rostral dorsal thalamic nucleus; RF, reticular formation; SNr, substantia nigra, pars reticulata; STh, subthalamus; Str, striatum; T, tectum mesencephali; Tor, torus semicircularis; VP, ventral pallidum; VTh, ventral thalamus.
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 References
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 Further Reading
    Bachy I Berthon J and Rétaux S (2002) Defining pallial and subpallial divisions in the developing Xenopus forebrain. Mechanisms of Development. 117: 163–172.
    book Ewert J-P (1989) "The release of visual behavior in toads. Stages of parallel/hierarchical information processing". In: Ewert J-P and Arbib MA (eds) Visuomotor Coordination, Amphibians, Comparisons, Models and Robots, pp 39–120. New York: Plenum.
    Feng AS Hall JC and Gooler DM (1990) Neural basis of sound pattern recognition in anurans. Progress in Neurobiology. 34: 313–329.
    Kay JN Hannigan P and Kelley DB (1999) Trophic effects of androgen: development and hormonal regulation of neuron number in a sexually dimorphic vocal motor nucleus. Journal of Neurobiology. 40: 375–385.
    Kelley DB (1997) Generating sexually differentiated songs. Current Opinion in Neurobiology. 7: 839–843.
    Lin W-Y and Feng AS (2003) GABA is involved in spatial unmasking in the frog auditory midbrain. The Journal of Neuroscience. 23: 8143–8151.
    Marín O Smeets WJAJ and González A (1998) Basal ganglia organization in amphibians: evidence for a common pattern in tetrapods. Progress in Neurobiology. 55: 363–397.
    book Ten Donkelaar HJ (1998) "Urodeles". In: Nieuwenhuys R (ed.) The central nervous system of Vertebrates, vol 2, pp. 1045–1150. Berlin: Springer.
    book Ten Donkelaar HJ (1998) "Anurans". In: Nieuwenhuys R (ed.) The central nervous system of Vertebrates, vol. 2, pp. 1051–1314. Berlin: Springer.
    Yamaguchi A and Kelley DB (2000) Generating sexually differentiated vocal patterns: laryngeal nerve and EMG recordings from vocalizing male and female African clawed frogs (Xenopus laevis). Journal of Neuroscience. 20: 1559–1567.

Related Sub-Topics:

Organisation of the Nervous System | Adaptive Evolution | Diversification of Plants and Animals
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Article Title: Amphibian Brains
 
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Smeets, Wilhelmus JAJ, and González, Agustín(Jan 2006) Amphibian Brains. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1038/npg.els.0004095]