Chronic Changes in Inputs to Dorsal Y Neurons Accompany VOR Motor Learning

2006 ◽  
Vol 95 (3) ◽  
pp. 1812-1825 ◽  
Author(s):  
Pablo M Blazquez ◽  
Yutaka Hirata ◽  
Stephen M. Highstein
Keyword(s):  
Motor Learning ◽  
Brain Stem ◽  
Purkinje Cells ◽  
Intact Animal ◽  
High Gain ◽  
Parallel Pathways ◽  
Gain Adaptation ◽  
Vor Adaptation ◽  
The Brain

Gain changes in the vestibuloocular reflex (VOR) during visual-vestibular mismatch stimulation serve as a model system for motor learning. The cerebellar flocculus and its target neurons in the brain stem (FTN) are candidates for the storage of these novel VOR gains. We have recently studied the changes in vertical flocculus Purkinje cells after chronic VOR motor learning. Recently we recorded Y neurons (a vertical type of FTNs) after chronic VOR motor learning and compared these records with vertical floccular Purkinje cells to document any changes in inputs to FTNs and understand how Y neurons and the vertical Purkinje cells fit into a general model for the vertical VOR. Analysis illustrates that the changes observed in Purkinje cells are not transferred to Y neurons, suggesting that the gain of their synaptic interconnection was modified. We quantified changes in both populations and employed simulations to study changes in parallel pathways to FTNs and to extract the role of the flocculus in VOR adaptation. Low-gain adaptation results in more drastic changes than its high-gain counterpart, causing increases in head velocity sensitivity in parallel pathways. Simulations suggest that cerebellar and brain stem plasticity both participate in novel VOR gain storage and that results obtained following floccular lesion are the product of different mechanisms than those operating in the intact animal.

scholarly journals Role of Nitric Oxide in Regulation of Brain Stem Circulation during Hypotension

1997 ◽  
Vol 17 (10) ◽  
pp. 1089-1096 ◽  
Author(s):  
Kazunori Toyoda ◽  
Kenichiro Fujii ◽  
Setsuro Ibayashi ◽  
Tetsuhiko Nagao ◽  
Takanari Kitazono ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Brain Stem ◽  
Topical Application ◽  
Basilar Artery ◽  
Group Versus ◽  
Control Group ◽  
Cranial Window ◽  
Severe Hypotension ◽  
The Brain

We tested the hypothesis that nitric oxide (NO) plays a role in CBF autoregulation in the brain stem during hypotension. In anesthetized rats, local CBF to the brain stem was determined with laser-Doppler flowmetry, and diameters of the basilar artery and its branches were measured through an open cranial window during stepwise hemorrhagic hypotension. During topical application of 10−5 mol/L and 10−4 mol/L Nω-nitro-L-arginine (L-NNA), a nonselective inhibitor of nitric oxide synthase (NOS), CBF started to decrease at higher steps of mean arterial blood pressure in proportion to the concentration of L-NNA in stepwise hypotension (45 to 60 mm Hg in the 10−5 mol/L and 60 to 75 mm Hg in the 10−4 mol/L L-NNA group versus 30 to 45 mm Hg in the control group). Dilator response of the basilar artery to severe hypotension was significantly attenuated by topical application of L-NNA (maximum dilatation at 30 mm Hg: 16 ± 8% in the 10−5 mol/L and 12 ± 5% in the 10−4 mol/L L-NNA group versus 34 ± 4% in the control group), but that of the branches was similar between the control and L-NNA groups. Topical application of 10−5 mol/L 7-nitro indazole, a selective inhibitor of neuronal NOS, did not affect changes in CBF or vessel diameter through the entire pressure range. Thus, endothelial but not neuronal NO seems to take part in the regulation of CBF to the the brain stem during hypotension around the lower limits of CBF autoregulation. The role of NO in mediating dilatation in response to hypotension appears to be greater in large arteries than in small ones.

Role of the brain stem in generating the 2- to 6-Hz oscillation in sympathetic nerve discharge

1993 ◽  
Vol 265 (5) ◽  
pp. R1026-R1035 ◽  
Author(s):  
S. Zhong ◽  
Z. S. Huang ◽  
G. L. Gebber ◽  
S. M. Barman
Keyword(s):  
Brain Stem ◽  
Sympathetic Nerve ◽  
Cervical Spinal Cord ◽  
Ventrolateral Medulla ◽  
Population Activity ◽  
A Value ◽  
Decerebrate Cats ◽  
The Brain ◽  
Nerve Discharge

We tested the hypothesis that brain stem circuits normally generate a 2- to 6-Hz oscillation in sympathetic nerve discharge (SND). Experiments were performed on baroreceptor-denervated decerebrate cats and urethan-anesthetized rats in which renal or splanchnic SND was recorded along with field potentials (population activity) from sites in the rostral ventrolateral medulla, medullary raphe, or medullary lateral tegmental field. Our major findings were as follows. 1) Population activity recorded from the three medullary regions contained a 2- to 6-Hz oscillation. 2) The 2- to 6-Hz oscillation in population activity recorded from some medullary sites was correlated to that in SND. Peak coherence in the 2- to 6-Hz band approached a value of 1 in some cases. 3) Whereas cervical spinal cord transection abolished or markedly reduced SND, the 2- to 6-Hz oscillation in medullary activity was essentially unchanged. These results support the view that the 2- to 6-Hz oscillation in SND can be generated in the brain stem of cats and rats.

scholarly journals Response Properties of Nucleus Reticularis Lateralis Neurons After Electroacupuncture Stimulation in Rats

2010 ◽  
Vol 38 (05) ◽  
pp. 869-880 ◽  
Author(s):  
Kentaro Moritaka ◽  
Jorge L. Zeredo ◽  
Mari Kimoto ◽  
Fajar H. Nasution ◽  
Takafumi Hirano ◽  
...  
Keyword(s):  
Brain Stem ◽  
Endogenous Opioids ◽  
Lateral Part ◽  
Response Properties ◽  
Acupuncture Stimulation ◽  
Nucleus Reticularis ◽  
Pain Transmission ◽  
Raphe Magnus ◽  
The Brain

A descending inhibitory mechanism from the periaqueductal gray (PAG) to the spinal cord through the nucleus raphe magnus (NRM) is strongly involved in endogenous analgesic system produced by acupuncture stimulation. In addition to the PAG to NRM system which descends in the medial pathway of the brain stem, the nucleus reticularis lateralis (NRL) situated in the lateral part of the brain stem is reported to play an important role in modulating centrifugal antinociceptive action. In the present study, to clarify the role of NRL in acupuncture analgesia, we investigated the response properties of NRL neurons to acupuncture stimulation. The majority of NRM-projecting NRL neurons were inhibited by electroacupuncture stimulation. This effect was antagonized by ionophoretic application of naloxone, indicating that endogenous opioids act directly onto these NRL neurons. By contrast, about half of spinal projecting NRL neurons were excited by electroacupuncture stimulation, suggesting that part of the NRL neurons may modulate pain transmission directly at the spinal level.

Role of the ventral surface of the brain stem in the hypotensive action of clonidine

1975 ◽  
Vol 34 (1) ◽  
pp. 151-156 ◽  
Author(s):  
Pascal Bousquet ◽  
Josiane Feldman ◽  
Jeanne Velly ◽  
Roger Bloch
Keyword(s):  
Brain Stem ◽  
Ventral Surface ◽  
Hypotensive Action ◽  
The Brain

scholarly journals Spike burst–pause dynamics of Purkinje cells regulate sensorimotor adaptation

2018 ◽  
Author(s):  
Niceto R. Luque ◽  
Francisco Naveros ◽  
Richard R. Carrillo ◽  
Eduardo Ros ◽  
Angelo Arleo
Keyword(s):  
Purkinje Cell ◽  
Purkinje Cells ◽  
Vestibular Nuclei ◽  
Response Patterns ◽  
Spike Burst ◽  
Vor Adaptation ◽  
Cell Firing ◽  
Cerebellar Purkinje Cells ◽  
Oculomotor Adaptation

AbstractCerebellar Purkinje cells mediate accurate eye movement coordination. However, it remains unclear how oculomotor adaptation depends on the interplay between the characteristic Purkinje cell response patterns, namely tonic, bursting, and spike pauses. Here, a spiking cerebellar model assesses the role of Purkinje cell firing patterns in vestibular ocular reflex (VOR) adaptation. The model captures the cerebellar microcircuit properties and it incorporates spike-based synaptic plasticity at multiple cerebellar sites. A detailed Purkinje cell model reproduces the three spike-firing patterns that are shown to regulate the cerebellar output. Our results suggest that pauses following Purkinje complex spikes (bursts) encode transient disinhibition of targeted medial vestibular nuclei, critically gating the vestibular signals conveyed by mossy fibres. This gating mechanism accounts for early and coarse VOR acquisition, prior to the late reflex consolidation. In addition, properly timed and sized Purkinje cell bursts allow the ratio between long-term depression and potentiation (LTD/LTP) to be finely shaped at mossy fibre-medial vestibular nuclei synapses, which optimises VOR consolidation. Tonic Purkinje cell firing maintains the consolidated VOR through time. Importantly, pauses are crucial to facilitate VOR phase-reversal learning, by reshaping previously learnt synaptic weight distributions. Altogether, these results predict that Purkinje spike burst-pause dynamics are instrumental to VOR learning and reversal adaptation.Author SummaryCerebellar Purkinje cells regulate accurate eye movement coordination. However, it remains unclear how cerebellar-dependent oculomotor adaptation depends on the interplay between Purkinje cell characteristic response patterns: tonic, high-frequency bursting, and post-complex spike pauses. We explore the role of Purkinje spike burst-pause dynamics in VOR adaptation. A biophysical model of Purkinje cell is at the core of a spiking network model, which captures the cerebellar microcircuit properties and incorporates spike-based synaptic plasticity mechanisms at different cerebellar sites. We show that Purkinje spike burst-pause dynamics are critical for (1) gating the vestibular-motor response association during VOR acquisition; (2) mediating the LTD/LTP balance for VOR consolidation; (3) reshaping synaptic efficacy distributions for VOR phase-reversal adaptation; (4) explaining the reversal VOR gain discontinuities during sleeping.

scholarly journals Deletion of the voltage-gated calcium channel, CaV1.3, causes deficits in motor performance and associative learning

2020 ◽  
Author(s):  
Marisol Lauffer ◽  
Hsiang Wen ◽  
Bryn Myers ◽  
Ashley Plumb ◽  
Krystal Parker ◽  
...  
Keyword(s):  
Motor Learning ◽  
Associative Learning ◽  
Motor Performance ◽  
Social Preference ◽  
Neural Circuits ◽  
Social Deficits ◽  
Voltage Gated ◽  
Voltage Gated Calcium Channels ◽  
The Brain

AbstractL-type voltage-gated calcium channels (LVGCCs) are important regulators of neuronal activity and are widely expressed throughout the brain. One of the major LVGCC isoforms in the brain is CaV1.3. Mice lacking CaV1.3 (CaV1.3 KO) have impairments in fear conditioning and depressive-like behaviors, which have been linked to the role of CaV1.3 in hippocampal and amygdala function. Genetic variation in CaV1.3 has been linked to a variety of psychiatric disorders, including autism and schizophrenia, which are associated with motor, learning, and social deficits. Here, we explored whether CaV1.3 plays a role in these behaviors. We found that CaV1.3 KO mice have deficits in rotarod learning despite normal locomotor function. Deletion of CaV1.3 is also associated with impaired associative learning on the Erasmus Ladder. We did not observe any impairments in CaV1.3 KO mice on assays of anxiety-like, depression-like, or social preference behaviors. Our results suggest an important role for CaV1.3 in neural circuits involved in motor learning and concur with previous data showing its involvement in associative learning.

Neural basis for motor learning in the vestibuloocular reflex of primates. I. Changes in the responses of brain stem neurons

1994 ◽  
Vol 72 (2) ◽  
pp. 928-953 ◽  
Author(s):  
S. G. Lisberger ◽  
T. A. Pavelko ◽  
D. M. Broussard
Keyword(s):  
Eye Movements ◽  
Motor Learning ◽  
Firing Rate ◽  
Brain Stem ◽  
Head Rotation ◽  
Head Motion ◽  
Vestibuloocular Reflex ◽  
Neural Basis ◽  
Ventral Paraflocculus ◽  
The Brain

1. We recorded from neurons in the brain stem of monkeys before and after they had worn magnifying or miniaturizing spectacles to cause changes in the gain of the vestibuloocular reflex (VOR). The gain of the VOR was estimated as eye speed divided by head speed during passive horizontal head rotation in darkness. Electrical stimulation in the cerebellum was used to identify neurons that receive inhibition at monosynaptic latencies from the flocculus and ventral paraflocculus (flocculus target neurons or FTNs). Cells were studied during smooth pursuit eye movements with the head stationary, fixation of different positions, cancellation of the VOR, and the VOR evoked by rapid changes in head velocity. 2. FTNs were divided into two populations according to their responses during pursuit with the head stationary. The two groups showed increased firing during smooth eye motion toward the side of recording (Eye-ipsiversive or E-i) or away from the side of recording (Eye-contraversive or E-c). A higher percentage of FTNs showed increased firing rate for contraversive pursuit when the gain of the VOR was high (> or = 1.6) than when the gain of the VOR was low (< or = 0.4). 3. Changes in the gain of the VOR had a striking effect on the responses during the VOR for the FTNs that were E-c during pursuit with the head stationary. Firing rate increased during contraversive VOR eye movements when the gain of the VOR was high or normal and decreased during contraversive VOR eye movements when the gain of the VOR was low. Changes in the gain of the VOR caused smaller changes in the responses during the VOR of FTNs that were E-i during pursuit with the head stationary. We argue that motor learning in the VOR is the result of changes in the responses of individual FTNs. 4. The responses of E-i and E-c FTNS during cancellation of the VOR depended on the gain of the VOR. Responses tended to be in phase with contraversive head motion when the gain of the VOR was low and in phase with ipsiversive head motion when the gain of the VOR was high. Comparison of the effect of motor learning on the responses of FTNs during cancellation of the VOR with the results of similar experiments on horizontal-gaze velocity Purkinje cells in the flocculus and ventral paraflocculus suggests that the brain stem vestibular inputs to FTNs are one site of motor learning in the VOR.(ABSTRACT TRUNCATED AT 400 WORDS)

Sign in / Sign up

Export Citation Format

Share Document