Cerebellar decussation of fibres from the nucleus reticularis tegmenti pontis in the brain of the albino rat

1978 ◽  
Vol 34 (8) ◽  
pp. 1039-1041 ◽  
Author(s):  
P. A. Brown ◽  
J. B. Carman
Keyword(s):  
Albino Rat ◽  
Nucleus Reticularis Tegmenti Pontis ◽  
Nucleus Reticularis ◽  
The Brain

scholarly journals Effect of Pharmacological Inactivation of Nucleus Reticularis Tegmenti Pontis on Saccadic Eye Movements in the Monkey

2006 ◽  
Vol 95 (6) ◽  
pp. 3698-3711 ◽  
Author(s):  
Chris R. S. Kaneko ◽  
Albert F. Fuchs
Keyword(s):  
Peak Velocity ◽  
Saccadic Eye Movements ◽  
It Projects ◽  
Related Activity ◽  
Considerable Difficulty ◽  
Nucleus Reticularis Tegmenti Pontis ◽  
Nucleus Reticularis ◽  
Oculomotor Vermis ◽  
Vertical Saccades ◽  
The Brain

The superior colliculus (SC) provides signals for the generation of saccades via a direct pathway to the brain stem burst generator (BG). In addition, it sends saccade-related activity to the BG indirectly through the cerebellum via a relay in the nucleus reticularis tegmenti pontis (NRTP). Lesions of the oculomotor vermis, lobules VIc and VII, and inactivation of the caudal fastigial nucleus, the cerebellar output nucleus to which it projects, produce saccade dysmetria but have little effect on saccade peak velocity and duration. We expected similar deficits from inactivation of the NRTP. Instead, injections as small as 80 nl into the NRTP first slowed ipsiversive saccades and then gradually reduced their amplitudes. Postinjection saccades had slower peak velocities and longer durations than preinjection saccades with similar amplitudes. Contraversive saccades retained their normal kinematics. When the gains of ipsiversive saccades to 10° target steps had fallen to their lowest values (0.28 ± 0.19; mean ± SD; n = 10 experiments), the gains of contraversive saccades to 10° target steps had decreased very little (0.82 ± 0.11). Eventually, ipsiversive saccades did not exceed 5°, even to 20° target steps. Moreover, these small remaining saccades apparently were made with considerable difficulty because their latencies increased substantially. When ipsiversive saccade gain was at its lowest, the gain and kinematics of vertical saccades to 10° target steps exhibited inconsistent changes. We argue that our injections did not compromise the direct SC pathway. Therefore these data suggest that the cerebellar saccade pathway does not simply modulate BG activity but is required for horizontal saccades to occur at all.

Smooth-Pursuit Eye-Movement Deficits With Chemical Lesions in Macaque Nucleus Reticularis Tegmenti Pontis

1999 ◽  
Vol 82 (3) ◽  
pp. 1178-1186 ◽  
Author(s):  
David A. Suzuki ◽  
Tetsuto Yamada ◽  
Rebecca Hoedema ◽  
Robert D. Yee
Keyword(s):  
Eye Movements ◽  
Smooth Pursuit ◽  
Ibotenic Acid ◽  
Frontal Eye Field ◽  
Smooth Pursuit Eye Movements ◽  
Pontine Nucleus ◽  
Nucleus Reticularis Tegmenti Pontis ◽  
Pursuit Eye Movements ◽  
Nucleus Reticularis ◽  
Dorsolateral Pontine Nucleus

Anatomic and neuronal recordings suggest that the nucleus reticularis tegmenti pontis (NRTP) of macaques may be a major pontine component of a cortico-ponto-cerebellar pathway that subserves the control of smooth-pursuit eye movements. The existence of such a pathway was implicated by the lack of permanent pursuit impairment after bilateral lesions in the dorsolateral pontine nucleus. To provide more direct evidence that NRTP is involved with regulating smooth-pursuit eye movements, chemical lesions were made in macaque NRTP by injecting either lidocaine or ibotenic acid. Injection sites first were identified by the recording of smooth-pursuit-related modulations in neuronal activity. The resulting lesions caused significant deficits in both the maintenance and the initiation of smooth-pursuit eye movements. After lesion formation, the gain of constant-velocity, maintained smooth-pursuit eye movements decreased, on the average, by 44%. Recovery of the ability to maintain smooth-pursuit eye movements occurred over ∼3 days when maintained pursuit gains attained normal values. The step-ramp, “Rashbass” task was used to investigate the effects of the lesions on the initiation of smooth-pursuit eye movements. Eye accelerations averaged over the initial 80 ms of pursuit initiation were determined and found to be decremented, on the average, by 48% after the administration of ibotenic acid. Impairments in the initiation and maintenance of smooth-pursuit eye movements were directional in nature. Upward pursuit seemed to be the most vulnerable and was impaired in all cases independent of lesioning agent and type of pursuit investigated. Downward smooth pursuit seemed more resistant to the effects of chemical lesions in NRTP. Impairments in horizontal tracking were observed with examples of deficits in ipsilaterally and contralaterally directed pursuit. The results provide behavioral support for the physiologically and anatomic-based conclusion that NRTP is a component of a cortico-ponto-cerebellar circuit that presumably involves the pursuit area of the frontal eye field (FEF) and projects to ocular motor-related areas of the cerebellum. This FEF-NRTP-cerebellum path would parallel a middle and medial superior temporal cerebral cortical area-dorsolateral pontine nucleus-cerebellum pathway also known to be involved with regulating smooth-pursuit eye movements.

Multiple zonal projections of the nucleus reticularis tegmenti pontis to the cerebellar cortex of the rat

2002 ◽  
Vol 15 (11) ◽  
pp. 1854-1858 ◽  
Author(s):  
M. F. Serapide ◽  
R. Parenti ◽  
M. R. Pantò ◽  
A. Zappalà ◽  
F. Cicirata
Keyword(s):  
Cerebellar Cortex ◽  
Nucleus Reticularis Tegmenti Pontis ◽  
Nucleus Reticularis

scholarly journals 60 YEARS OF NEUROENDOCRINOLOGY: MEMOIR: Geoffrey Harris and my brush with his unit

2015 ◽  
Vol 226 (2) ◽  
pp. T1-T11 ◽  
Author(s):  
Geoffrey Raisman
Keyword(s):  
Sexual Differentiation ◽  
Preoptic Area ◽  
Suprachiasmatic Nuclei ◽  
Imaging Studies ◽  
Albino Rat ◽  
Rat Retina ◽  
Personal Story ◽  
Short Period ◽  
The Brain ◽  
Mutant Rat

Geoffrey Harris is chiefly known for his demonstration of the control of the pituitary gland by the portal vessels coming from the hypothalamus. This does not do justice to his extraordinary contribution to biology. Harris' life's work was central in demonstrating the brain/body interactions by which animals and humans adapt to their environment, and above all the control of that most crucial and proximate of all evolutionary events – reproduction. In this brief review, I have tried to put Geoffrey Harris' work in the context of the scientific thinking at the time when he began his work, and above all, the contribution of his mentor, FHA Marshall, on whose towering shoulders Harris rose. But this is mainly my personal story, in which I have tried to show the debt that my work owed to Harris and especially to my dear friend, the late Keith Brown-Grant in Harris' team. I myself was never an endocrinologist, but over a short period in the early 1970s, under the influence of such inspirational mentors, and using purely anatomical methods, I was able to demonstrate sexual dimorphism and hormone-dependent sexual differentiation in the connections of the preoptic area, regeneration of the median eminence, the ultrastructure of apoptosis, the requirement for the suprachiasmatic nuclei in reproductive rhythms, the existence of non-rod or cone photoreceptors in the albino rat retina and, later, the expression of vasopressin by solitary (one in 600) magnocellular neurons in the polydipsic di/di Brattleboro mutant rat; this phenomenon was subsequently shown to be due to a+1 reading frameshift. I end this brief overview by mentioning some of the abiding and fascinating mysteries of the endocrine memory of the brain that arise from Harris' work on the control of the endocrines, and by pointing out how the current interest in chronobiology emphasises what a Cinderella the endocrine mechanisms have become in current brain imaging studies.

Effects of Certain Indole Amines on Electrical Activity of the Nervous System

1956 ◽  
Vol 185 (3) ◽  
pp. 601-606 ◽  
Author(s):  
Alan G. Slocombe ◽  
Hudson Hoagland ◽  
Lillian S. Tozian
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Electrical Activity ◽  
Lysergic Acid ◽  
Subcortical Structures ◽  
Albino Rat ◽  
Site Of Action ◽  
The Central Nervous System ◽  
Recovery From Anesthesia ◽  
The Brain

Lysergic acid diethylamide (LSD), 5-hydroxytryptamine, and adrenochrome were shown to have properties similar to epinephrine in their effects on the spontaneous electrical activity in the brain of the albino rat. The effects of these drugs were shown to be determined by the type of anesthetic used. In Pentothal-anesthetized animals, profound reduction of the electrical activity in both frequency and amplitude was found in response to these drugs, while in ether-anesthetized animals there was no significant effect. There was a tendency for LSD to increase electrical activity when injected following recovery from anesthesia. The significance of this differential response is discussed with respect to structures in the central nervous system primarily affected by ether and Pentothal, and it is suggested that the site of action of these compounds is in Pentothal-sensitive nonspecific pathways. The site of the depressive action of these drugs with Pentothal is further defined by the fact that both cortical and subcortical structures were equally affected, while respiratory and cardio-regulatory centers were not significantly depressed. This implicates one of the lower nonspecific centers with widespread cortical and subcortical projections.

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