Difference between revisions of "Si4"
(Created page with 'Si4 is a Neuron in ''Melibe'' == Basic information == Category: Melibe') |
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| − | + | [[Si3]] is a neuron in ''[[Melibe]]'' | |
== Basic information == | == Basic information == | ||
| + | [[Image: xxx.jpg|right|thumb|200px|Dye fill of Si4 shows xxx.]] | ||
| + | *'''Names and Aliases''' - Swim Interneuron 4, Si4, Si4<sub>''Mel''</sub>. | ||
| + | *'''Species:''' ''[[Melibe]] leonina'' | ||
| + | *'''NeuronBank ID:''' [http://neuronbank.org/Mexxx Mexxx] | ||
| + | *'''Neurotransmitter:''' Unknown. | ||
| + | There is one Si4 in each pedal ganglion. The axon projects out the large pedal-pedal connective (PP2). [[Si3]] is a member of the central pattern generator circuit for lateral-flexion swimming. Si3 fires rhythmic bursts during a swim motor pattern. | ||
| + | |||
| + | == Identification == | ||
| + | '''Anatomy: ''' | ||
| + | * The Si4 oma located on dorsal surface and in the center of each pedal ganglion around [[Si2]] vicinity. | ||
| + | * Projections into neuropil of pedal ganglion and also out large pedal-pedal connective (PP2 according to nomenclature in Newcomb et al, 2006) to contralateral pedal ganglion. | ||
| + | * The main axon shows a characteristic "?" mark bend in each pedal ganglion. | ||
| + | * Fine branches are constrained near the soma and at the end of the axon, showing characteristic T-shape endings in both pedal ganglia. | ||
| + | |||
| + | '''Connectivity''' | ||
| + | * Contralateral Si4s mutually inhibit each other, monosynaptically. | ||
| + | * Si4 is electrically coupled to the contralateral [[Si1]] and [[Si2]]. The connection is stronger with Si1 than Si2. | ||
| + | * Si4 receives excitatory synaptic input from the contralateral Si1 and Si2. | ||
| + | * Si4 makes inhibitory synapses onto the contralateral Si3. The synaptic potential has a fast depolarizing phase and a slow hyperpolarizing phase. | ||
| + | |||
| + | '''Electrophysiology:''' | ||
| + | [[Image: xxx.jpg|right|thumb|300px|Simultaneous intracellular recordings from xx and xxx illustrate the swim motor pattern.]] | ||
| + | * Action potentials recorded from the Si4 soma are remarkably shorter (approx. 20-30 mV in height) than those in other swim interneurons; Si4 spikes never overshoot. | ||
| + | * When a swim motor pattern is not being expressed, Si4 is generally silent. | ||
| + | * During a swim motor pattern, Si4 fires rhythmic bursts together with the contralateral [[Si1]] and Si2 burst. | ||
| + | * Injection of a brief square current into one of the Si4 pair can phase shift the swim motor pattern. | ||
| + | * Injection of steady current into Si4 slightly affect the swim motor pattern. | ||
| + | |||
| + | == References == | ||
| + | # Sakurai A, Gunaratne CA, Katz PS (2014) Two interconnected kernels of reciprocally inhibitory interneurons underlie alternating left-right swim motor pattern generation in the mollusc Melibe leonina. J Neurophysiol DOI: 10.1152/jn.00261.2014. | ||
[[Category: Melibe]] | [[Category: Melibe]] | ||
Revision as of 17:32, 30 June 2014
Basic information
File:Xxx.jpg
Dye fill of Si4 shows xxx.
- Names and Aliases - Swim Interneuron 4, Si4, Si4Mel.
- Species: Melibe leonina
- NeuronBank ID: Mexxx
- Neurotransmitter: Unknown.
There is one Si4 in each pedal ganglion. The axon projects out the large pedal-pedal connective (PP2). Si3 is a member of the central pattern generator circuit for lateral-flexion swimming. Si3 fires rhythmic bursts during a swim motor pattern.
Identification
Anatomy:
- The Si4 oma located on dorsal surface and in the center of each pedal ganglion around Si2 vicinity.
- Projections into neuropil of pedal ganglion and also out large pedal-pedal connective (PP2 according to nomenclature in Newcomb et al, 2006) to contralateral pedal ganglion.
- The main axon shows a characteristic "?" mark bend in each pedal ganglion.
- Fine branches are constrained near the soma and at the end of the axon, showing characteristic T-shape endings in both pedal ganglia.
Connectivity
- Contralateral Si4s mutually inhibit each other, monosynaptically.
- Si4 is electrically coupled to the contralateral Si1 and Si2. The connection is stronger with Si1 than Si2.
- Si4 receives excitatory synaptic input from the contralateral Si1 and Si2.
- Si4 makes inhibitory synapses onto the contralateral Si3. The synaptic potential has a fast depolarizing phase and a slow hyperpolarizing phase.
Electrophysiology:
File:Xxx.jpg
Simultaneous intracellular recordings from xx and xxx illustrate the swim motor pattern.
- Action potentials recorded from the Si4 soma are remarkably shorter (approx. 20-30 mV in height) than those in other swim interneurons; Si4 spikes never overshoot.
- When a swim motor pattern is not being expressed, Si4 is generally silent.
- During a swim motor pattern, Si4 fires rhythmic bursts together with the contralateral Si1 and Si2 burst.
- Injection of a brief square current into one of the Si4 pair can phase shift the swim motor pattern.
- Injection of steady current into Si4 slightly affect the swim motor pattern.
References
- Sakurai A, Gunaratne CA, Katz PS (2014) Two interconnected kernels of reciprocally inhibitory interneurons underlie alternating left-right swim motor pattern generation in the mollusc Melibe leonina. J Neurophysiol DOI: 10.1152/jn.00261.2014.
