The Red Nucleus And Mesencephalic Tegmentum In A Ranid Amphibian - A Cytoarchitectonic And Hrp Connectional Study
accessory optic; amphibian; Behavioral Sciences; brain-stem; cerebellar afferents; cerebellum; descending spinal pathways; edinger-westphal nucleus; frog; horseradish-peroxidase; interstitial nucleus; midbrain; Neurosciences & Neurology; north-american; oculomotor; of cajal; opossum; red nucleus; reticular formation; retrograde tracer; rubrospinal tract; topological analysis; Zoology
Movement control in vertebrates is a complex function that is known to involve several parallel systems. In amphibians, which lack the isocortical structures shown in mammals to initiate and control voluntary movements, supraspinal motor control systems have received surprisingly little attention. Because amphibians lack a corticospinal equivalent, coordination and control of all movement strategies must take place in non-cortical, supraspinal integrating centers. The rubro-cerebello-rubrospinal circuit is likely to represent a major motor control system in such vertebrates. In this anatomical investigation four mesencephalic tegmentospinal projection nuclei are described in ranid amphibians (Rana catesbiana and Rana pipiens): reticular formation, accessory optic complex, interstitial nucleus of Cajal, and the red nucleus. The red nucleus, which shows no distinct somatotopic organization, can be distinguished because it is the only one of the four that is predominantly contralateral in its projections. Horseradish peroxidase injections into the tegmentum and the cerebellum demonstrated that the red nucleus also maintains reciprocal connections with the cerebellum via the deep cerebellar nucleus. These connections could not be localized to any distinct region in the deep cerebellar nuclear mass, suggesting that this represents a single cerebellar recipient nucleus. Thus, anuran amphibians are shown to possess the major pathways that comprise the rubro-cerebello-rubrospinal circuitry in mammals.
Larsonprior L J; Cruce W L R
Brain Behavior and Evolution
1992
1992-12
Journal Article or Conference Abstract Publication
<a href="http://doi.org/10.1159/000113918" target="_blank" rel="noreferrer noopener">10.1159/000113918</a>
Immunoreactivity Of Bufo-marinus Heart For Atrial-natriuretic-factor
amphibian; atrial natriuretic factor; body; factor anf; frog-heart; heart; immunohistochemistry; localization; peptide; ventricles; water regulation; Zoology
Gilloteaux J
Belgian Journal of Zoology
1991
1991-12
Journal Article or Conference Abstract Publication
n/a
Immunohistochemistry and spinal projections of the reticular formation in the northern leopard frog, Rana pipiens
american opossum; amphibian; brain-stem; central-nervous-system; descending; enkephalin; intermediolateral cell column; Neurosciences & Neurology; pathways; reticulospinal; serotonin; somatostatin; somatostatin-immunoreactive; stem reticulospinal nuclei; structures; substance P; substance-p-like; tyrosine-hydroxylase; ventral medulla-oblongata; Zoology
Over 30 nuclei have been identified in the reticular formation of rats, but only a small number of distinct reticular nuclei have been recognized in frogs. We used immunohistochemistry, retrograde tracing, and cell morphology to identify nuclei within the brainstem of Rana pipiens. FluoroGold was injected into the spinal cord, and, in the same frogs, antibodies to enkephalin, substance P, somatostatin, and serotonin were localized in adjacent sections. We identified many previously unrecognized reticular nuclei. The rhombencephalic reticular formation contained reticularis (r.) dorsalis; r. ventralis, pars alpha and pars beta; r. magnocellularis; r. parvocellularis; r. gigantocellularis; r. paragigantocellularis lateralis and dorsalis; r. pontis caudalis, pars alpha and pars beta; nucleus visceralis secundarius; r. pontis oralis, pars medialis and pars lateralis; raphe obscurus; raphe pallidus; raphe magnus; and raphe pontis. The mesencephalic reticular formation contained locus coeruleus-subcoeruleus, r. cuneiformis, r. subcuneiformis, raphe dorsalis-raphe centralis superior, and raphe linearis. Thus, the reticular formation of frog, which is an anamniote, is organized complexly and is similar to the reticular formation in amniotes. Because many of these nuclei may be homologous to reticular nuclei in mammals, we used mammalian terminology for frog reticular nuclei. (C) 1999 Wiley-Liss, Inc.
Adli D S H; Stuesse S L; Cruce W L R
Journal of Comparative Neurology
1999
1999-02
Journal Article or Conference Abstract Publication
n/a
Does behavioural hypothermia promote post-exercise recovery in cold-submerged frogs?
amphibian; anuran amphibians; behavioural hypothermia; body size; bufo-marinus; bullfrogs; exhaustive exercise; frog; hypoxia; Life Sciences & Biomedicine - Other Topics; maximal oxygen; mechanisms; metabolic recovery; overwintering; Rana; rana-catesbeiana; recovery; temperature; temperature selection; temporaria; thermoregulation
At the low temperatures of the overwintering environment of the frog Rana temporaria, small changes in ambient temperature have large effects on metabolism and behaviour, especially since Q(10) values are often greatly elevated in the cold. How the overwintering aquatic frog copes with variable thermal environments in terms of its overall activity metabolism and recovery from pursuit by predators is poorly understood, as is the role of behavioural thermoregulation in furthering recovery from intense activity, Exhaustive exercise was chosen as the method of evaluating activity capacity (defined by time to exhaustion, total distance swum and number of leg contractions before exhaustion) and was determined at 1.5 and 7 degrees C, Other cohorts of frogs were examined at both temperatures to determine the metabolic (acid-base, lactate, glucose, ATF and creatine phosphate) and respiratory responses to exercise in cold-submerged frogs. Finally, temperature preference before and after exercise was determined in a thermal gradient to define the importance of behavioural thermoregulation on the recovery rates of relevant metabolic and respiratory processes. Activity capacity was significantly reduced in frogs exercised at 1.5 versus 7 degrees C, although similar levels of tissue acid-base metabolites and lactate were reached, Blood pH, plasma PCO2 and lactate levels recovered more rapidly at 1.5 degrees C than at 7 degrees C; however, intracellular pH and the recovery of tissue metabolite levels were independent of temperature. Resting aerobic metabolic rates were strongly affected by temperature (Q(10)=3.82); however, rates determined immediately after exercise showed a reduced temperature sensitivity (Q(10)=1.67) and, therefore, a reduced factorial aerobic scope, Excess oxygen consumption recovered to resting values after 5-6.25 h, and 67% recovery times tended to be slightly faster at the lower temperatures, Exercise in the cold, therefore, provided an immediately higher factorial scope, which could be involved in the faster rate of recovery of blood lactate levels in the colder frogs, In addition, exercise significantly lowered the preferred temperature of the frogs from 6.7 to 3.6 degrees C for nearly 7 h, after which they returned to their normal, unstressed preferred temperatures. Thus, a transient behavioural hypothermia in the skin-breathing, overwintering frog may be an important strategy for minimising post-exercise stress and maintaining aerobic metabolism during recovery from intense activity.
Tattersall G J; Boutilier R G
Journal of Experimental Biology
1999
1999-03
Journal Article
n/a