Vertical banding evoked by electrical stimulation of the brain in anaesthetized green sunfish, Lepomis cyanellus, and bluegills, Lepomis macrochirus

1980 ◽  
Vol 84 (1) ◽  
pp. 149-160
Author(s):  
D. H. Bauer ◽  
L. S. Demski
Keyword(s):  
Electrical Stimulation ◽  
Transition Zone ◽  
Lepomis Macrochirus ◽  
Optic Tract ◽  
Colour Change ◽  
The Body ◽  
Lepomis Cyanellus ◽  
Green Sunfish ◽  
The Brain ◽  
Stimulation Of

A pattern of dark vertical bands is a characteristic agonistic display in the green sunfish, Lepomis cyanellus and the bluegill, L. macrochirus. The rapidity with which the display can appear and disappear indicates that it is neurally controlled. Electrical stimulation of the brain was carried out in anaesthetized green sunfish and bluegills to map those regions from which this colour change can be elicited. Banding was evoked by stimulation of sites near the midline in the preoptic area, ventral thalamic-dorsal hypothalmic transition zone, the midbrain tegmentum (just dorsal to the nucleus prerotundus pars medialis), in and near the torus semicricularis, in the basal midbrain (region of the crossing tectobulbar tracts), and in the rostral basomedial medulla. A ‘transition’ zone was located basally in the middle medulla, caudal to which only paling was evoked. Areas found to be negative for evoked banding included the telencephalic lobe, the inferior lobe of the hypothalamus, the optic tract, the optic tectum, the body and valvula of the cerebellum and the caudal medulla. It is postulated that the vertical banding pattern is made up of a separate, selectively controlled system of dermal melanophores. The possible neural mechanisms controlling banding are discussed.

Effects of Temperature on Responses of the Gonads of Green Sunfish (Lepomis cyanellus) to Treatment with Carp Pituitaries and Testosterone Propionate

1973 ◽  
Vol 30 (7) ◽  
pp. 905-912 ◽  
Author(s):  
Calvin M. Kaya
Keyword(s):  
Low Temperatures ◽  
Elevated Temperatures ◽  
Testosterone Propionate ◽  
Lepomis Cyanellus ◽  
Pituitary Glands ◽  
Effects Of Temperature ◽  
Gonadal Recrudescence ◽  
Green Sunfish ◽  
The Brain ◽  
Stimulation Of

Previous investigations have demonstrated that stimulation of gonadal recrudescence in the green sunfish (Lepomis cyanellus) depends on the concurrent presence of long photoperiods (15 hr) and elevated temperatures (> 15 C). The present investigation indicates that recrudescence can be stimulated in seasonally regressed ovaries and testes by injections of a crude extract of fish pituitary glands, and in testes by testosterone propionate, but only under elevated temperature. The low temperatures that block gonadal responses to long photoperiods also effectively prevent gonadal responses to administered hormones. These observations indicate that the responsiveness of the gonads of this species to stimulating hormones is markedly modified by temperature; however, the results do not obviate the possibility that secretion of gonadotropins by the brain–pituitary system may also be affected.

Excitation and Inhibition of the Reflex Eye Withdrawal of The Crab Carcinus

1967 ◽  
Vol 46 (3) ◽  
pp. 475-485
Author(s):  
D. C. SANDEMAN
Keyword(s):  
Motor Neuron ◽  
Optic Tract ◽  
The Body ◽  
Motor Axon ◽  
Single Motor ◽  
Burst Length ◽  
The Brain ◽  
Cathodal Stimulation ◽  
Stimulation Of

1. Damage to the statocysts or section of the oesophageal connectives of Carcinus causes repeated ‘spontaneous’ eye withdrawals or ‘blinking’ on the damaged side. 2. When the eyes and brain are isolated from the body, repetitive blinking persists and concomitant bursts of large impulses appear in a single motor axon in the optic tract. The length of these bursts varies from 80 to 180 impulses and the interburst intervals from 5 to 60 sec. There is no obvious correlation between burst length and interburst interval. 3. The bursts are inhibited by stimulating the inside half of the ipsilateral oesophageal connective or initiated by stimulation of the oculomotor and tegumentary nerves. If stimulated with a continuous train of pulses these pathways also cause an increase or decrease in the interburst intervals. 4. The actively spiking portion of the eye-withdrawal motor neuron extends into the brain at least as far as the tegumentary/antennary neuropile. Here it is particularly sensitive to cathodal stimulation, yielding trains of spikes to maintained d.c. stimulation. This point is considered to be near the spike initiating locus for the bursts.

Convergence of heterotopic nociceptive information onto neurons of caudal medullary reticular formation in monkey (Macaca fascicularis)

1990 ◽  
Vol 63 (5) ◽  
pp. 1118-1127 ◽  
Author(s):  
L. Villanueva ◽  
K. D. Cliffer ◽  
L. S. Sorkin ◽  
D. Le Bars ◽  
W. D. Willis
Keyword(s):  
Electrical Stimulation ◽  
Reticular Formation ◽  
Mechanical Stimulation ◽  
Background Activity ◽  
The Body ◽  
Thermal Stimulation ◽  
Medullary Reticular Formation ◽  
Nociceptive Information ◽  
Noxious Mechanical Stimulation ◽  
Stimulation Of

1. Recordings were made in anesthetized monkeys from neurons in the medullary reticular formation (MRF) caudal to the obex. Responses of 19 MRF neurons to mechanical, thermal, and/or electrical stimulation were examined. MRF neurons exhibited convergence of nociceptive cutaneous inputs from widespread areas of the body and face. 2. MRF neurons exhibited low levels of background activity. Background activity increased after periods of intense cutaneous mechanical or thermal stimulation. Nearly all MRF neurons tested failed to respond to heterosensory stimuli (flashes, whistle sounds), and none responded to joint movements. 3. MRF neurons were excited by and encoded the intensity of noxious mechanical stimulation. Responses to stimuli on contralateral limbs were greater than those to stimuli on ipsilateral limbs. Responses were greater to stimuli on the forelimbs than to stimuli on the hindlimbs. 4. MRF neurons responded to noxious thermal stimulation (51 degrees C) of widespread areas of the body. Mean responses from stimulation at different locations were generally parallel to those for noxious mechanical stimulation. Responses increased with intensity of noxious thermal stimulation (45-50 degrees C). 5. MRF neurons responded with one or two peaks of activation to percutaneous electrical stimulation applied to the limbs, the face, or the tail. The differences in latency of responses to stimulating two locations along the tail suggested that activity was elicited by activation of peripheral fibers with a mean conduction velocity in the A delta range. Stimulation of the contralateral hindlimb elicited greater responses, with lower thresholds and shorter latencies, than did stimulation of the ipsilateral hindlimb. 6. Electrophysiological properties of monkey MRF neurons resembled those of neurons in the medullary subnucleus reticularis dorsalis (SRD) in the rat. Neurons in the caudal medullary reticular formation could play a role in processing nociceptive information. Convergence of nociceptive cutaneous input from widespread areas of the body suggests that MRF neurons may contribute to autonomic, affective, attentional, and/or sensory-motor processes related to pain.

scholarly journals Muscular Movements in Man, and their Evolution in the Infant: a Study of Movement in Man, and its Evolution, together with Inferences as to the Properties of Nerve-Centres and their Modes of Action in expressing Thought

1889 ◽  
Vol 35 (149) ◽  
pp. 23-44 ◽  
Author(s):  
Francis Warner
Keyword(s):  
Brain Area ◽  
Muscular Contraction ◽  
The Body ◽  
Brain Areas ◽  
Modes Of Action ◽  
Central Nerve System ◽  
Nerve System ◽  
The Brain ◽  
Compound Series ◽  
Stimulation Of

(1) Movement in mau has long been a subject of profitable study. Visible movement in the body is produced by muscular contraction following upon stimulation of the muscles by efferent currents passing from the central nerve-system. Modern physiological experiments have demonstrated that when a special brain-area discharges nerve-currents, these are followed by certain visible movements or contraction of certain muscles corresponding. So exact are such reactions, as obtained by experiment upon the brain-areas, that movements similar to those produced by experimental excitation of a certain brain-area may be taken as evidence of action in that area, or as commencing in discharge from that area (see Reinforcement of Movements, 35; Compound Series of Movements, 34).

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