Partial correlation method

Scientists worked on several researches to identify the behavior of the brain. They have been working on different types of programs aiming the connection between neurons. Scientists found that Calcium Imaging Data can be used in order to solve this problem. Calcium Imaging allows real time and simultaneous observation s of neuron activities from the thousands of neurons which is in the brain. This provides an individual time series which will represents the fluorescent intensity when messages are passing between neurons. There are many methods scientists have used in order to learn the behavior of the neurons using calcium Imaging Data. Considering all of these methods partial correlation method is being used mostly because this method helps to differentiate direct connections with indirect connections. Partial correlation method measures the unconditional linear dependence between variables and it should not be able to filter out indirect interactions between neurons. This method is basically builds on Transfer entropy method to measure the association between neurons.

 Partial correlation method in Connectomics.

This can be considered as one of the best methodology to reconstruct the neuron network. This is done by removing the relationship of neural spike trains with other neurons. The detect ability decreases with the number of neurons included in the analysis and increases with the recording time. This consists of two major parts. One is to identify the peak activities of neurons which will be detected by the raw signals while other one is to interpret the interconnection of neurons from partial correlation information.

                                                                     The density of the partial covariance will give additional information about the direction and the type of the connections. When considering a large neural network many problems arrive. There may be a problem to identify at what extent the association between processes because of the direct connection between two neurons or there may be a problem to identify whether the observed correlation is due to a common input from other neurons. These problems were handled by  the method of partialization. partial spectral coherence was used in analyzing patialization ( | R_ab|c) |² ) in the frequency domain with the partial spectral densities. Where,

                                     R_ab|c) | =  

For investigating undirected graphs which will visualize the correlation structure of a multivariate point process, partial correlation graphs can be used. This will lead to identify the synaptic connections from the neural spike data. Here it is not possible to say that this partial correlation graphs will directly reflect the physiological connectivity structure of the neuron network. Using a directed graph we can indicate a direct connection from vertex a to vertex b when there is a synaptic connection from one neuron to another. We can denote a as the parent and b as the child. So that edges will not be coinciding either. To obtain the partial correlation graph we have to join all the parents of a joint child by an edge. By observing this directed graph we can identify vertices without children and their adjacent edges can be correctly identify from the partial co variance density scales. After these vertices have been removed from the graph and using remaining set we can identify all directed edges.

Cosmetics- Calcium Chanel Imaging

                                          The Brain consist of a structural and functional properties of interconnected neurons. The main challenge is to identify the connections between neurons. Scientists have already revealed that when a neuron receives or sends a message it transmits an electric pulse. Even though we can’t see them even using any advanced microscopes. So, they were not succeeded. And there are millions of neurons in our brain. So, there are many messages are transmitting between them. The main objective of the scientists was to identify this connection between these neurons.

Methodology  
                                 Scientists done lots of researches about this and they finally revealed that there is a method. They come to know that Fluorescent Calcium’s ions will help to detect the neurons. When a neuron receives a signal that neuron will fire. Calcium is an essential intracellular messenger in mammalian neurons. At rest, most neurons have an intracellular calcium concentration of about 50–100 nM that can rise transiently during electrical activity to levels that are ten to 100 times higher. At any given moment, the cytosolic calcium concentration is determined by the balance between calcium influx and efflux as well as by the exchange of calcium with internal stores
  

The method is also applicable to slices of brain and to recordings of the surface of the brain after it has been exposed surgically.  These being a long time inspiration for computational intelligence Systems. Understanding the behavior of the neurons will reveal the Intelligence systems in general. This will helps to find out the alterations caused to the brain because of the diseases.

Identify the Connection between neurons in the Brain

The Brain consist of a structural and functional properties of interconnected neurons.

What are neurons?

Neuron can be defined as a cell within the Nervous System which is the basic working unit of the Brain.These neurons communicate in a unique way.They will transmit information to other nerve cells, muscles and Gland cells.A mammalian neuron consists of  cell body, axon and dendrites. The cell body consist of a nucleus and a cytoplasm. axons are extended from the cell body. Dendrites are also extended from the cell body and communication is done by dendrites in between neurons.When a neuron receives or sends message they transmit an electrical pulse along their axons.And there's a myelin sheath covered by the axons which will accelerate the transmission of the electrical signals.

How to observe physically?

Knowing the connections between neurons in the brain is the key to understanding learning and memory.Even though it is hard to trace the connections between neurons even using modern advanced microscopes. Therefore a special method is used to detect those connections. Scientists have revealed that this can be detected using Florescent Calcium ions.Using these calcium ions they could observe the firing of the neurons.When a neuron receives a signal that neuron will fire.To experiment we use cultured neurons. The method is also applicable to slices of brain and to recordings of the surface of the brain after it has been exposed surgically.

 These being a long time inspiration for computational intelligence Systems.Understanding the behavior of the neurons will reveal the Intelligence systems in general.This will helps to find out the alterations caused to the brain because of the diseases.