The motor program and role of the meropodite sensory organs (the chordotonal organs MC-1, MC-2 and the myochordotonal organ MCO) in extension of the merocarpodite (M-C) joint of the claw was examined during an antennal-evoked defense response. Recordings from the meropodite extensor muscle indicated that the tonic extensor motoneuron was primarily responsible for M-C joint extension. The phasic extensor motoneuron was co-activated with the tonic motoneuron in only 48% of the responses. Tonic motoneuron discharge was elevated in those responses in which the phasic motoneuron was active. Inactivation of individual meropodite sensory organs did not alter the tonic motoneuron response. Simultaneous inactivation of all 3 organs reduced tonic motoneuron discharge by 47%. Phasic motoneuron discharge was reduced following inactivation of the individual MC-1, MC-2 and MCO organs as well as in the sham operated group. Following inactivation of all 3 organs phasic motoneuron activity ceased. These results suggest that feedback from the M-C sensory organs during an active extension response is positive and redundant.

Download full-text PDF

Source
http://dx.doi.org/10.1016/0006-8993(86)90218-0DOI Listing

Publication Analysis

Top Keywords

tonic motoneuron
16
sensory organs
12
motoneuron discharge
12
phasic motoneuron
12
motoneuron
9
motor program
8
program role
8
meropodite sensory
8
mc-1 mc-2
8
m-c joint
8

Similar Publications

Norepinephrine in vertebrates and its invertebrate analog, octopamine, regulate the activity of neural circuits. We find that, when hungry, larvae switch activity in type II octopaminergic motor neurons (MNs) to high-frequency bursts, which coincide with locomotion-driving bursts in type I glutamatergic MNs that converge on the same muscles. Optical quantal analysis across hundreds of synapses simultaneously reveals that octopamine potentiates glutamate release by tonic type Ib MNs, but not phasic type Is MNs, and occurs via the G-coupled octopamine receptor (OAMB).

View Article and Find Full Text PDF

Virus-mediated delivery of single-chain antibody targeting TDP-43 protects against neuropathology, cognitive impairment and motor deficit caused by chronic cerebral hypoperfusion.

Exp Neurol

January 2025

CERVO Brain Research Centre, Québec, Québec G1J 2G3, Canada; Department of Psychiatry and Neuroscience, Université Laval, Québec City G1V 0A6, Canada. Electronic address:

Chronic cerebral hypoperfusion induced by permanent unilateral common carotid artery occlusion in mice was recently found to induce an age-dependent formation of insoluble cytoplasmic TDP-43 aggregates reminiscent of pathological changes found in human vascular dementia. In this model, the gradual deregulation of TDP-43 homeostasis in cortical neurons was associated with marked cognitive and motor deficits. To target the TDP-43-mediated toxicity in this model, we generated an adeno-associated virus vector encoding a single-chain antibody against TDP-43, called scFv-E6, designed for pan-neuronal transduction following intravenous administration.

View Article and Find Full Text PDF

Action Potential Firing Patterns Regulate Dopamine Release via Voltage-Sensitive Dopamine D2 Autoreceptors in Mouse Striatum In Vivo.

Adv Sci (Weinh)

December 2024

State Key Laboratory of Membrane Biology, National Biomedical Imaging Center and Institute of Molecular Medicine, College of Future Technology, Peking-Tsinghua Center for Life Sciences, PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing, 100871, China.

Dopamine (DA) in the striatum is vital for motor and cognitive behaviors. Midbrain dopaminergic neurons generate both tonic and phasic action potential (AP) firing patterns in behavior mice. Besides AP numbers, whether and how different AP firing patterns per se modulate DA release remain largely unknown.

View Article and Find Full Text PDF

For individuals with motor complete spinal cord injury (SCI), previous works have shown that spared motor neurons below the injury level can still be voluntarily controlled. In this study, we investigated the behavior of these neurons after SCI by analyzing neural and spatial properties of individual motor units using high-density surface electromyography (HDsEMG) and ultrasound imaging. The dataset for this study is based on motor unit data from our previous work (Oliveira et al.

View Article and Find Full Text PDF

Selective enhancement of synaptic GABA signaling mediated by GABA-A receptors has been previously reported to promote functional recovery after ischemic stroke, while tonic GABA signaling has been detrimental. To identify agents that enhance synaptic signaling, we synthesized GABA-A ligands based on three chemotypes with affinity values p= 6.44-8.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!