Relating network synaptic connectivity and network activity in the lobster (Panulirus interruptus) pyloric network

Area of Science:

• Neuroscience
• Systems Neuroscience
• Crustacean Neurobiology

Background:

• The lobster pyloric network exhibits complex synaptic connectivity, making it challenging to isolate the function of individual neurons.
• Understanding the contribution of specific neurons, like the Lateral Pyloric (LP) and Ventricular Dilator (VD) neurons, is crucial for deciphering network dynamics.

Purpose of the Study:

• To investigate the functional role of LP and VD neurons in the lobster pyloric network.
• To determine the impact of LP and VD neuron removal on pyloric network phasing and spiking activity, independent of changes in network period.

Main Methods:

• Functional removal of LP and VD neurons via hyperpolarization.
• Manipulation of pyloric network period using current injection into a pacemaker neuron.
• Quantification of pyloric neuron activity and phasing across different network periods and experimental conditions.

Main Results:

• In most cases, removing LP or VD neurons had a surprisingly small effect on the activity of their postsynaptic partners.
• Observed alterations in postsynaptic activity upon neuron removal were inconsistent across preparations.
• This suggests that LP and VD neurons play a limited role in determining pyloric activity under normal physiological conditions.

Conclusions:

• The study indicates that LP and VD neurons may not be primary drivers of pyloric network activity in lobsters.
• Inconsistencies in results suggest potential variability in pyloric network cellular/synaptic properties or neuromodulatory influences between individual animals.
• Further research may be needed to explore the conditions under which these synapses contribute significantly to network function.