Climbing fiber (CF) input to the cerebellum is thought to instruct associative motor memory formation through its effects on multiple sites within the cerebellar circuit. We used adeno-associated viral delivery of channelrhodopsin-2 (ChR2) to inferior olivary neurons to selectively express ChR2 in CFs, achieving nearly complete transfection of CFs in the caudal cerebellar lobules of rats. As expected, optical stimulation of ChR2-expressing CFs generates complex spike responses in individual Purkinje neurons (PNs); in addition we found that such stimulation recruits a network of inhibitory interneurons in the molecular layer. This CF-driven disynaptic inhibition prolongs the postcomplex spike pause observed when spontaneously firing PNs receive direct CF input; such inhibition also elicits pauses in spontaneously firing PNs not receiving direct CF input. Baseline firing rates of PNs are strongly suppressed by low-frequency (2 Hz) stimulation of CFs, and this suppression is partly relieved by blocking synaptic inhibition. We conclude that CF-driven, disynaptic inhibition has a major influence on PN excitability and contributes to the widely observed negative correlation between complex and simple spike rates. Because they receive input from many CFs, molecular layer interneurons are well positioned to detect the spatiotemporal patterns of CF activity believed to encode error signals. Together, our findings suggest that such inhibition may bind together groups of Purkinje neurons to provide instructive signals to downstream sites in the cerebellar circuit.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3532857 | PMC |
http://dx.doi.org/10.1523/JNEUROSCI.3916-12.2012 | DOI Listing |
PLoS One
January 2025
Physical Culture Institute Ludong University, City Yantai, Shandong Province, China.
The target of rapamycin(TOR)gene is closely related to metabolism and cellular aging, but it is unclear whether the TOR pathways mediate endurance exercise against the accelerated aging of skeletal muscle induced by high salt intake. In this study, muscular TOR gene overexpression and RNAi were constructed by constructing MhcGAL4/TOR-overexpression and MhcGAL4/TORUAS-RNAi systems in Drosophila. The results showed that muscle TOR knockdown and endurance exercise significantly increased the climbing speed, climbing endurance, the expression of autophagy related gene 2(ATG2), silent information regulator 2(SIR2), and pparγ coactivator 1(PGC-1α) genes, and superoxide dismutases(SOD) activity, but it decreased the expression of the TOR gene and reactive oxygen species(ROS) level, and it protected the myofibrillar fibers and mitochondria of skeletal muscle in Drosophila on a high-salt diet.
View Article and Find Full Text PDFPhysiol Behav
January 2025
Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. Electronic address:
C1q/TNF-related protein 14 (CTRP14), also known as C1q-like 1 (C1QL1), is a synaptic protein predominantly expressed in the brain. It plays a critical role in the formation and maintenance of the climbing fiber-Purkinje cell synapses, ensuring that only one single winning climbing fiber from the inferior olivary neuron synapses with the proximal dendrites of Purkinje cells during the early postnatal period. Loss of CTRP14/C1QL1 results in incomplete elimination of supernumerary climbing fibers, leading to multiple persistent climbing fibers synapsing with the Purkinje cells.
View Article and Find Full Text PDFBMC Musculoskelet Disord
January 2025
Department of Orthopaedics and Traumatology, Faculty of Medicine, Dokuz Eylül University, İzmir, 35340, Turkey.
Background: Menisci, one of the most important anatomical structures of the knee joint, plays a role in load transfer, stability, shock absorption, prevention of articular cartilage degeneration, and proprioception. Type I collagen, the main component of the meniscus, and type II collagen fibers play an important role in the stability of the knee joint. This study aimed to evaluate the effects of Naturagen® 4 Joint product containing type I, II, and III collagen on pain, quality of life, and physical functions in patients with meniscopathy.
View Article and Find Full Text PDFInt J Sports Physiol Perform
December 2024
School of Sport Science, UiT The Arctic University of Norway, Tromsø, Norway.
Introduction: Women have generally lower body size and lean- to fat-mass ratio, lower maximal anaerobic power due to a lower muscle mass, and fewer fast-twitch fibers, although they can show higher resistance to fatigue or greater metabolic flexibility than men. These factors are well known and explain the sex differences in endurance sports such as distance running (10%-12%). Several of these factors-particularly the differences in body composition and skeletal-muscle characteristics-may directly impact vertical displacement and uphill performance.
View Article and Find Full Text PDFElife
December 2024
Université Paris Cité, CNRS, Saints-Pères Paris Institute for the Neurosciences, Paris, France.
Granule cells of the cerebellum make up to 175,000 excitatory synapses on a single Purkinje cell, encoding the wide variety of information from the mossy fibre inputs into the cerebellar cortex. The granule cell axon is made of an ascending portion and a long parallel fibre extending at right angles, an architecture suggesting that synapses formed by the two segments of the axon could encode different information. There are controversial indications that ascending axon (AA) and parallel fibre (PF) synapse properties and modalities of plasticity are different.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!