System, method and applications involving identification of biological circuits such as neurological characteristics
Various aspects are directed to systems and methods for assessing neural activity of a neural region having multiple subfields. In certain embodiments, a method includes evoking a cellular electrical response in at least one subfield due to neural activity in the neural region, capturing image data of the electrical response at a level sufficiently detailed in space and time to differentiate between polarization-based events of two respective portions of the subfield, and then assessing neural activity by correlating space and time information, from the captured data, for the two respective portions of the sub-field. Other more specific aspects of the invention involve different preparation and neural stimulation approaches which can vary depending on the application.
1. A method for assessing neural activity of a neural tissue in a neural region having multiple subfields, the method comprising:
evoking a cellular electrical response in at least one subfield of the neural tissue due to neural activity in the neural region, wherein neuronal cells in the neural region express a light-activated ion channel and/or a light-activated ion pump protein;
capturing image data of the cellular electrical response at space and time limits of resolution that allow for the differentiation between polarization-based events of two portions of the at least one subfield, wherein each of the two portions comprises a group of neurons; and
assessing neural activity by correlating space and time information, from the captured data, for the two portions of the at least one subfield.
2. The method of claim 1 , wherein evoking an electrical response comprises exogenously affecting the neural region.
3. The method of claim 1 , wherein evoking an electrical response comprises stimulating the neural region.
4. The method of claim 1 , wherein evoking an electrical response comprises passively monitoring electrical activity occurring in an otherwise unstimulated environment.
5. The method of claim 1 , wherein the cellular electrical response is evoked by optical stimulation of the light-activated ion channel and/or the light-activated ion pump protein.
6. A system for assessing neural activity, the system comprising:
a composition comprising a nucleic acid encoding a light-activated ion channel and/or a light-activated ion pump protein;
a stimulator configured to evoke a cellular electrical response in at least one subfield of a neural tissue in a neural region having multiple subfields by optically stimulating neuronal cells of the neural region that comprise the nucleic acid and express the light-activated ion channel and/or the light-activated ion pump protein;
an imager configured to capture image data of the cellular electrical response at space and time limits of resolution that allow for differentiation between polarization-based events of two portions of the at least one subfield, wherein each of the two portions comprises a group of neurons; and
a processor configured for assessing neural activity, wherein assessing neural activity comprises correlating space and time information, from the captured image data, for the two portions of the at least one subfield to produce correlation results.
7. The system according to claim 6 , further comprising a composition for staining the neural tissue, wherein the composition comprises at least one of: a voltage sensitive dye, and a calcium sensitive dye.
8. The system according to claim 6 , wherein the correlation results comprise a correlation between a signal strength of a stimulation profile and each pixel in the image data, and wherein the processor is further configured for:
determining the correlation between the signal strength of the stimulation profile and each pixel in the image data;
determining a cross-correlation amplitude for each pixel based on the determined correlation;
determining a cross-correlation phase for each pixel based on the determined correlation;
identifying areas of interest as a function of a spatial location of each pixel and the determined cross-correlations; and
limiting pixel variations in the image data that are not in the identified areas of interest.
9. The system according to claim 8 , wherein limiting pixel variations in the image data that are not in the identified areas of interest comprises median filtering the image data.
10. The system according to claim 9 , wherein the median filtering comprises median filtering with a 3×3 pixel window.
11. The system according to claim 6 , wherein the processor is further configured for: assessing target locations for a treatment that includes a physical intervention.
12. The system according to claim 6 , further comprising a computer arrangement comprising:
the processor; and
a storage medium storing computer-executable data, wherein, when the computer-executable data is executed by the processor, the processor assesses neural activity by correlating space and time information, from the captured data, for the two portions of the at least one subfield.
13. The system according to claim 6 , wherein assessing neural activity further comprises comparing the correlation results with and without a treatment for the neural region, wherein the treatment is at least one of: a pharmacological chemical based substance, a nonchemical-based therapeutic treatment, a neural-invasive treatment, a neural-genesis treatment, and a neural-modulation treatment.
14. The system according to claim 6 , wherein assessing neural activity further comprises assessing endophenotypes for a predictive value relative to a disorder.
15. The system according to claim 6 , wherein assessing neural activity further comprises assessing a role of one or more subfields within a neural circuit.
16. The system according to claim 6 , wherein neural activity is assessed relative to a depressed state of the neural region.
17. The system according to claim 6 , wherein neural activity is assessed relative to one or more of: Alzheimer's disease, mild cognitive impairment, autism, bipolar disorder, schizophrenia, and Down Syndrome.
18. The system according to claim 6 , wherein:
the space limit of resolution is less than a centimeter;
the time limit of resolution is less than 500 milliseconds; and
the polarization-based events involve at least one of: depolarization events and hyperpolarization events.
19. The system according to claim 6 , wherein the space limit of resolution is less than about a millimeter.
20. The system according to claim 6 , wherein the subfields include dentate gyrus (DG) and CA1 subfields of the hippocampus.
21. The system according to claim 6 , wherein the neural region is selected from the group consisting of hypothalamus, frontal cortex, entorhinal cortex, cingulate cortex, mammillary bodies, septum, bed nucleus of stria terminalis, amygdala, and accumbens.
22. The system according to claim 6 , wherein the light-activated ion channel and/or the light-activated ion pump protein is at least one of: a channel-rhodopsin (ChR2), and a halorhodopsin (NpHR).
23. The system according to claim 6 , wherein the neural tissue is a brain slice.