fb0m+@andrew.cmu.edu (Franklin Boyle) (04/03/91)
Does anyone know a good reference(s) for answering questions about neural connectivity in the brain (as opposed to what people model), e.g. How many axon terminals are there per neuron on average? How many different dendritic trees do these synapse to on average? How far laterally do these connections range? What is the nature and number of dentritic-dendritic connections in interneurons? in output neurons? Are there significant connectivity differences in different layers of the cortex? etc... I'm particularly interested in any recent publications which give numbers or reasonable approximations as opposed to just saying "many" or "far reaching" etc. Thanks, Frank Boyle
ddoherty@ics.uci.edu (Donald Doherty) (04/04/91)
In article <cby=xKG00WBK81y7h1@andrew.cmu.edu> fb0m+@andrew.cmu.edu (Franklin Boyle) writes: >Does anyone know a good reference(s) for answering questions >about neural connectivity in the brain (as opposed to what people >model), e.g. How many axon terminals are there per neuron on average? >How many different dendritic trees do these synapse to on average? >How far laterally do these connections range? What is the >nature and number of dentritic-dendritic connections in >interneurons? in output neurons? Are there significant connectivity >differences in different layers of the cortex? etc... > >I'm particularly interested in any recent publications which give >numbers or reasonable approximations as opposed to just saying >"many" or "far reaching" etc. > >Thanks, >Frank Boyle Unfortunately, there are very few data in the primary literature addressing the above questions. The primary reason is the extreme difficulty and often imposibility of doing the necessary experiment. Few *want* to do the experiments. (It can take a few years to reconstruct a single pyramidal neuron with its dendrites and synaptic input using serial sections. After all of the work one still does not know where the synapses originated from!) Having said that, there is one neuroscientist that I know of that has made a career of this tedious, but important, work. Ed White has brought a lot of his data together into a book called: Cortical Circuits: Synaptic Organization of the Cerebral Cortex: Structure, Function, and Theory. (1989) Edward L. White. Birkhauser. Otherwise, what data there are on the subject are scattered about in the primary literature. Don D. Dept. of Psychobiology University of California Irvine, CA 92717
kingsley@hpwrce.HP.COM (Kingsley Morse) (04/05/91)
I'm interested in quantitative descriptions of synaptic connectivity also.