Transformation of Visual Signals by Inhibitory Interneurons in Retinal Circuits
authors: Pablo D. Jadzinsky, Stephen A. Baccus
doi: 10.1146/annurev-neuro-062012-170315
CITATION
Jadzinsky, P. D., & Baccus, S. A. (2013). Transformation of Visual Signals by Inhibitory Interneurons in Retinal Circuits. Annual Review of Neuroscience, 36(1), 403–428. https://doi.org/10.1146/annurev-neuro-062012-170315
ABSTRACT
One of the largest mysteries of the brain lies in understanding how higher-level computations are implemented by lower-level operations in neurons and synapses. In particular, in many brain regions inhibitory interneurons represent a diverse class of cells, the individual functional roles of which are unknown. We discuss here how the operations of inhibitory interneurons influence the behavior of a circuit, focusing on recent results in the vertebrate retina. A key role in this understanding is played by a common representation of the visual stimulus that can be applied at different stages. By considering how this stimulus representation changes at each location in the circuit, we can understand how neuron-level operations such as thresholds and inhibition yield circuit-level computations such as how stimulus selectivity and gain are controlled by local and peripheral visual stimuli.
fleeting notes
retina is a testing ground for understanding circuit function
five basic cell types
- but more than 50 subtypes suggest diversity of functions
the functino of a sensory system is to provide info for behaviors
sometimes the releationship between the output of the retina and behavior is not clear
- but because there is exact control of the experiments
how can the function of an internneuron be understood?
- how does the stimulus produce the interneurons resposne
- how does the stimulus produce the circuit output
- how does the interneuron output contribute to the circuit output
the linear receptive field does not describe the enitre relationship between stimulus and response
- so now people use linear-nonlinear models that use a linear spatiotemporal filder and a threshold
- but even this does not describe responses to broad ranges of stimuli
one simple function of an inhibitory neuron is sign inversion
the A17 cell creates temporal filtering without spatial pooling by having independent synaptic contacts
crossover inhibition reduces amount of vesicle release needed to convey a signal
- cells can be more efficient at transmitting info
starburst amacrine cells are direction selective
- the dendrites of the cells process signal locally - different dendrites can have different direction preferences
highlights
“By considering how this stimulus representation changes at each location in the circuit, we can understand how neuron-level operations such as thresholds and inhibition yield circuit-level computations such as how stimulus selectivity and gain are controlled by local and peripheral visual stimuli.”Page
“Component parts often have very simple functions, and it is only when one considers how many of these pieces interact, as well as the overall function, that one can understand the role of a component of a system.”Page 2