scispace - formally typeset
Search or ask a question
Topic

Toad

About: Toad is a research topic. Over the lifetime, 1624 publications have been published within this topic receiving 28732 citations.


Papers
More filters
Journal ArticleDOI
01 Jul 1992-Toxicon
TL;DR: Alterations in the mitochondria and the presence of myelin figures and degenerative foci in the cytoplasm may probably be regarded as consequences of the cellular injury provoked by compression.

42 citations

Journal ArticleDOI
TL;DR: Spinal functions in amphibians are controlled by CA innervation from brain centers that can easily be compared with their counterparts in amniotes, and a remarkable difference was observed with respect to the diencephalic CA projections.
Abstract: Immunohistochemical studies with antibodies against tyrosine hydroxylase, dopamine, and noradrenaline have revealed that the spinal cord of anuran, urodele, and gymnophionan (apodan) amphibians is abundantly innervated by catecholaminergic (CA) fibers and terminals. Because intraspinal cells occur in all three orders of amphibians CA, it is unclear to what extent the CA innervation of the spinal cord is of supraspinal origin. In a previous study, we showed that many cell groups throughout the forebrain and brainstem project to the spinal cord of two anurans (the green frog, Rana perezi, and the clawed toad, Xenopus laevis), a urodele (the Iberian ribbed newt, Pleurodeles waltl), and a gymnophionan (the Mexican caecilian, Dermophis mexicanus). To determine the exact site of origin of the supraspinal CA innervation of the amphibian spinal cord, retrograde tracing techniques were combined with immunohistochemistry for tyrosine hydroxylase in the same sections. The double-labeling experiments demonstrated that four brain centers provide CA innervation to the amphibian spinal cord: 1.) the ventrolateral component of the posterior tubercle in the mammillary region, 2.) the periventricular nucleus of the zona incerta in the ventral thalamus, 3.) the locus coeruleus, and 4.) the nucleus of the solitary tract. This pattern holds for all three orders of amphibians, except for the CA projection from the nucleus of the solitary tract in gymnophionans. There are differences in the strength of the projections (based on the number of double-labeled cells), but in general, spinal functions in amphibians are controlled by CA innervation from brain centers that can easily be compared with their counterparts in amniotes. The organization of the CA input to the spinal cord of amphibians is largely similar to that described for mammals. Nevertheless, by using a segmental approach of the CNS, a remarkable difference was observed with respect to the diencephalic CA projections.

42 citations

Journal ArticleDOI
TL;DR: Net water flow Jw, was measured across the abdominal skin of the toad Bufo marinus with a volumetric, automatic technique that allows for averaging Jw over time intervals as short as 1 sec.
Abstract: 1. Net water flow J(w), was measured across the abdominal skin of the toad Bufo marinus with a volumetric, automatic technique that allows for averaging J(w) over time intervals as short as 1 sec.2. Basal J(w) was very stable and corresponded to a coefficient of osmotic flow, L(PD), of ca. 15 x 10(-7) cm sec(-1) atm(-1) (or to an osmotic water permeability coefficient, P(f), of 20 mum sec(-1)).3. Both vasopressin and the beta-adrenergic agonist, isoprenaline, triggered high hydrosmotic responses that could lead to P(f) values exceeding 250 mum sec(-1). The effect of isoprenaline was very reproducible while that of vasopressin varied considerably.4. Methohexital and propranolol selectively inhibited the hydrosmotic effects of vasopressin and isoprenaline, respectively, whereas amiloride and ouabain had no effect.5. Mutual inhibition was found between vasopressin and isoprenaline in skins very sensitive to vasopressin. In less sensitive skins isoprenaline further increased J(w) despite exposure of the epithelia to supramaximal concentrations of vasopressin.6. Differential reactivity to vasopressin was found between the skin and the bladder taken from the same toad. In some instances, the bladder responded normally to vasopressin while the skin was totally unresponsive, suggesting the presence of osmoregulatory mechanisms exerting a local modulation of the vasopressin action in different target epithelia of the same animal.

42 citations


Network Information
Related Topics (5)
Endoplasmic reticulum
48.3K papers, 2.4M citations
77% related
Secretion
24.8K papers, 1.2M citations
75% related
Membrane potential
18.7K papers, 939.6K citations
75% related
Cytoplasm
19.8K papers, 942.8K citations
74% related
Golgi apparatus
19.8K papers, 1M citations
73% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202348
2022118
202112
202012
201913
20188