The deep cerebellar nuclei (DCN) integrate various inputs to the cerebellum and form the final cerebellar outputs critical for associative sensorimotor learning. However, the functional relevance of distinct neuronal subpopulations within the DCN remains poorly understood. Here, we examined a subpopulation of mouse DCN neurons whose axons specifically project to the ventromedial (Vm) thalamus (DCN^Vm neurons), and found that these neurons represent a specific subset of DCN units whose activity varies with trace eyeblink conditioning (tEBC), a classical associative sensorimotor learning task. Upon conditioning, the activity of DCN^Vm neurons signaled the performance of conditioned eyeblink responses (CRs). Optogenetic activation and inhibition of the DCN^Vm neurons in well-trained mice amplified and diminished the CRs, respectively. Chemogenetic manipulation of the DCN^Vm neurons had no effects on non-associative motor coordination. Furthermore, optogenetic activation of the DCN^Vm neurons caused rapid elevated firing activity in the cingulate cortex, a brain area critical for bridging the time gap between sensory stimuli and motor execution during tEBC. Together, our data highlights DCN^Vm neurons' function and delineates their kinematic parameters that modulate the strength of associative sensorimotor responses.
Animals ; Blinking ; Cerebellar Nuclei/physiology* ; Cerebellum ; Mice ; Neurons/physiology* ; Thalamus

Synaptic plasticity of barrel cortex is one of the most widely studied topics in neuroscience in recent years. The primary somatosensory cortex of the rodent has a good topology character,which provides an ideal experimental model for plasticity study. This system displays very strong experience-dependent plasticity both during development and in adulthood. The changes of sensory cortex's neural circuit can induce experience-dependent plasticity. In the synaptic level,thalamocortical synapse is considered to be the main location of plasticity. In the circuit level,both synapses from layer 4 to layer 2/3 and those within layer 2/3 are also the necessary parts of achieving synaptic plasticity in primary somatosensory cortex. The GABAergic inhibitory circuit may be involved in this plasticity of S1, but the exact mechanism remains unknown.
Animals ; Neural Pathways ; physiology ; Neuronal Plasticity ; Somatosensory Cortex ; physiology ; Synapses ; physiology ; Thalamus ; physiology ; Vibrissae ; physiology

Acute pain is a warning protective sensation for any impending harm. However, chronic pain syndromes are often resistant diseases that may consume large amount of health care costs. It has been suggested by recent studies that pain perception may be formed in central neural networks via large-scale coding processes, which involves sensory, affective, and cognitive dimensions. Many central areas are involved in these processes, including structures from the spinal cord, the brain stem, the limbic system, to the cortices. Thus, chronic painful diseases may be the result of some abnormal coding within this network. A thorough investigation of coding mechanism of pain within the central neuromatrix will bring us great insight into the mechanisms responsible for the development of chronic pain, hence leading to novel therapeutic interventions for pain management.
Animals ; Cerebral Cortex ; physiology ; Humans ; Nociception ; physiology ; Pain ; physiopathology ; Thalamus ; physiology

Crossmodal information processing in sensory cortices has been reported in sparsely distributed neurons under normal conditions and can undergo experience- or activity-induced plasticity. Given the potential role in brain function as indicated by previous reports, crossmodal connectivity in the sensory cortex needs to be further explored. Using perforated whole-cell recording in anesthetized adult rats, we found that almost all neurons recorded in the primary somatosensory, auditory, and visual cortices exhibited significant membrane-potential responses to crossmodal stimulation, as recorded when brain activity states were pharmacologically down-regulated in light anesthesia. These crossmodal cortical responses were excitatory and subthreshold, and further seemed to be relayed primarily by the sensory thalamus, but not the sensory cortex, of the stimulated modality. Our experiments indicate a sensory cortical presence of widespread excitatory crossmodal inputs, which might play roles in brain functions involving crossmodal information processing or plasticity.
Animals ; Auditory Cortex/physiology* ; Neuronal Plasticity/physiology* ; Neurons ; Rats ; Thalamus ; Visual Cortex/physiology*

Acupuncture analgesia is involved in various functions of the whole nervous system. The spinal cord is the first station for processing and translating the acupuncture analgesia; the brain stem is the relay station for systematization, differentiation and analysis, excitation, synthesis of acupuncture analgesic message, playing an important role in acupuncture analgesia; the thalamus functions complicated analysis and comprehensive regulation on various messeges with many kinds of neurohumoral factors involved and it is a coordinate center for strengthening and controlling acupuncture analgesia; the limbic system and its nuclear groups with many neurotransmitters involved, play coordinate action on acupuncture analgesia; the cerebral cortex is the high center and functions not only excitation and inhibition processes, but also is a center for complicated regulation and command, strengthening acupuncture analgesia and inhibiting the excess, so as to exerts interaction of dynamic balance.
Acupuncture Analgesia ; Brain Stem ; physiology ; Cerebral Cortex ; physiology ; Humans ; Limbic System ; physiology ; Pain ; physiopathology ; Spinal Cord ; physiology ; Thalamus ; physiology

In contrast to the spinal control of erection, relatively little is known about the brain control. In the present review, we have outlined the role of brain structures involved in penile erection and provided a synopsis on the brain circuit of erection. Findings from both animal and human studies are discussed. Evidence suggests that the most important structures are the frontal lobe, cingulate gyrus, amygdala, thalamus and hypothalamus. Within the brain circuit of erection, the thalamus serves as a gate-controller in which all relevant information is evaluated and further processed to higher and lower centres.
Brain ; physiology ; Humans ; Male ; Models, Neurological ; Nerve Net ; Penile Erection ; Thalamus ; physiology

This study aims to explore the auditory response characteristics of the thalamic reticular nucleus (TRN) in awake mice during auditory information processing, so as to deepen the understanding of TRN and explore its role in the auditory system. By in vivo electrophysiological single cell attached recording of TRN neurons in 18 SPF C57BL/6J mice, we observed the responses of 314 recorded neurons to two kinds of auditory stimuli, noise and tone, applied to mice. The results showed that TRN received projections from layer six of the primary auditory cortex (A1). Among 314 TRN neurons, 56.05% responded silently, 21.02% responded only to noise and 22.93% responded to both noise and tone. The neurons with noise response can be divided into three patterns according to their response time: onset, sustain and long-lasting, accounting for 73.19%, 14.49% and 12.32%, respectively. The response threshold of the sustain pattern neurons was lower than those of the other two types. Under noise stimulation, compared with A1 layer six, TRN neurons showed unstable auditory response (P < 0.001), higher spontaneous firing rate (P < 0.001), and longer response latency (P < 0.001). Under tone stimulation, TRN's response continuity was poor, and the frequency tuning was greatly different from that of A1 layer six (P < 0.001), but their sensitivity to tone was similar (P > 0.05), and TRN's tone response threshold was much higher than that of A1 layer six (P < 0.001). The above results demonstrate that TRN mainly undertakes the task of information transmission in the auditory system. The noise response of TRN is more extensive than the tone response. Generally, TRN prefers high-intensity acoustic stimulation.
Rats ; Mice ; Animals ; Wakefulness ; Auditory Pathways/physiology* ; Rats, Wistar ; Mice, Inbred C57BL ; Thalamus/physiology*

OBJECTIVE: To detect the activation pattern of the thalamus in human by the functional magnetic resonance imaging (fMRI) with the electrical stimulation of different intensities, and to explore the mechanism of this area in pain modulation. METHODS: Ten healthy right-handed volunteers were given different electrical stimulations of 1-, 2-, and 3- times pain threshold respectively. The whole-brain was scanned simultaneously by GE 1.5T magnetic resonance imaging system. The data were postprocessed by analysis of functional neuroimages (AFNI) to establish the regional activity maps of the thalamus. RESULTS: Patterns of functional activity showed a positive linear relationship between the activation signals and stimulation intensity in bilateral thalamus, whereas the BOLD signal of bilateral medial thalamus demonstrated that the curve was similar to the exponential function. Meanwhile, the activation in the contralateral lateral thalamus (cThl), but not the contralateral medial thalamus (cThm), was prominent compared with the corresponding ipsilateral subregions, and only the lateral thalamus displayed a contralateral biased representation while the medial thalamus lacked this property. CONCLUSION Thalamus is one of the vital components in the pain modulation network, which can present spatial segregation activations with unique characteristics of stimulation intensity-response in each subregion. All the results are helpful to understand the crucial role of thalamus in processing the pain information.
Adult ; Electric Stimulation ; Female ; Humans ; Magnetic Resonance Imaging ; Male ; Pain ; physiopathology ; Pain Threshold ; Thalamus ; physiology

The pedunculopontine nucleus (PPN) is located in the dorso-lateral part of the ponto-mesencephalic tegmentum. The PPN is composed of two groups of neurons: one containing acetylcholine, and the other containing non-cholinergic neurotransmitters (GABA, glutamate). The PPN is connected reciprocally with the limbic system, the basal ganglia nuclei (globus pallidus, substantia nigra, subthalamic nucleus), and the brainstem reticular formation. The caudally directed corticolimbic-ventral striatal-ventral pallidal-PPN-pontomedullary reticular nuclei-spinal cord pathway seems to be involved in the initiation, acceleration, deceleration, and termination of locomotion. This pathway is under the control of the deep cerebellar and basal ganglia nuclei at the level of the PPN, particularly via potent inputs from the medial globus pallidus, substantia nigra pars reticulata and subthalamic nucleus. The PPN sends profuse ascending cholinergic efferent fibers to almost all the thalamic nuclei, to mediate phasic events in rapid-eye-movement sleep. Experimental evidence suggests that the PPN, along with other brain stem nuclei, is also involved in anti-nociception and startle reactions. In idiopathic Parkinson's disease (IPD) and parkinson plus syndrome, overactive pallidal and nigral inhibitory inputs to the PPN may cause sequential occurrences of PPN hypofunction, decreased excitatory PPN input to the substantia nigra, and aggravation of striatal dopamine deficiency. In addition, neuronal loss in the PPN itself may cause dopamine-r esistant parkinsonian deficits, including gait disorders, postural instability and sleep disturbances. In patients with IPD, such deficits may improve after posteroventral pallidotomy, but not after thalamotomy. One of the possible explanations for such differences is that dopamine-resistant parkinsonian deficits are mediated to the PPN by the descending pallido-PPN inhibitory fibers, which leave the pallido-thalamic pathways before they reach the thalamic targets.
Animal ; Basal Ganglia/cytology ; Human ; Mesencephalon/physiology* ; Mesencephalon/cytology ; Movement Disorders/etiology* ; Pons/physiology* ; Pons/cytology ; Thalamus/cytology

OBJECTIVETo investigate the relationship between limb tremor and neuronal firing in thalamus (Vim) and retrospectively review the clinical effects and safety of the surgical treatment of essential tremor (ET).

METHODSForty-two ET patients received microelectrode-guided thalamotomy and 11 cases were quantitatively evaluated with FAHN rating scales pre- and post-operatively.

RESULTSThere were electrophysiological tremor-related neurons in ventrolateral part of thalamus. Lesioning of those neurons abolished contralateral limb tremor in all of the patients. No permanent contralateral weakness, dysarthria and hemorrhage were observed.

CONCLUSION"Tremor cell" in thalamus plays a key role in the symptom of ET patients. Destruction of those cells may completely and permanently abolish tremor symptom.

Adult ; Aged ; Aged, 80 and over ; Electrophysiology ; Essential Tremor ; physiopathology ; surgery ; Female ; Follow-Up Studies ; Humans ; Male ; Middle Aged ; Neurons ; physiology ; Retrospective Studies ; Thalamus ; physiopathology ; surgery