?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=Revisiting+the+Concept+of+Identifiable+Neurons&rft.creator=Bullock%2C+Theodore&rft.subject=Behavioral+Biology&rft.subject=Computational+Neuroscience&rft.subject=Neuroanatomy&rft.subject=Neurophysiology&rft.description=Although+eutely+in+nematodes+was+known%2C+giant+neurons+in+several+taxa+and+unique+motor+neurons+to+leg+muscles+in+decapod+crustaceans%2C+the+idea+that+many+animals+have+many+identifiable+neurons+with+relatively+consistent+dynamical+properties+and+connections+was+only+slowly+established+in+the+late+1960s+and+early+1970s.+This+has+to+be+one+of+the+important+quiet+revolutions+in+neurobiology.+It+stimulated+a+vast+acquisition+of+specific+information+and+led+to+some+euphoria+in+the+degree+and+pace+of+understanding+activity+of+nervous+systems+and+consequent+behavior+in+terms+of+neuronal+connections+and+properties.+Some+implications%2C+problems+and+opportunities+for+new+discovery+are+developed.+The+distribution+of+identifiable+neurons+among+taxa+and+parts+of+the+nervous+system+is+not+yet+satisfactorily+known.+Their+evolution+may+have+been+a+case+of+several+independent+inventions.+The+degree+of+consistency+has+been+quantified+only+in+a+few+examples+and+the+plasticity+is+little+known.+Identified+neurons+imply+identifiable+circuits+but+whether+this+extends+to+discrete+systems%2C+functionally+definable%2C+seems+likely+to+have+several+answers+in+different+animals+or+sites.+Very+limited+attempts+have+been+made+to+extend+the+concept+to+cases+of+two+or+ten+or+a+hundred+fully+equivalent+neurons%2C+on+all+kinds+of+criteria.+These+attempts+suggest+a+much+smaller+redundancy+and+vaster+number+of+types+of+neurons+than+hitherto+believed.+Theory+as+well+as+empirical+information+has+not+yet+interpreted+the+range+of+systems+from+those+with+small+sets+of+relatively+reliable+neurons+to+those+with+large+numbers+of+parallel%2C+partially+redundant+units.+The+now+classical+notion+of+local+circuits+has+to+be+extended+to+take+account+and+find+roles+for+the+plethora+of+integrative+variables%2C+of+evidence+for+neural+processing+independent+of+spikes+and+classical+synapses%2C+of+spatial+configurations+of+terminal+arbors+and+dendritic+geometry%2C+of+modulators+and+transmitters%2C+degrees+of+rhythmicity+(regularity+varying+several+orders+of+magnitude)%2C+and+of+synchrony.+Adequate+language+and+models+need+to+go+beyond+%22circuits%22+in+any+engineering+sense.+Identifiable+neurons+can+contribute+to+a+broad+spectrum+of+issues+in+neurobiology.&rft.contributor=Leonard%2C+J.L.&rft.date=2000&rft.type=Journal+(Paginated)&rft.type=NonPeerReviewed&rft.format=text%2Fhtml&rft.identifier=http%3A%2F%2Fcogprints.org%2F1089%2F1%2Findentifiable_neuron.htm&rft.identifier=++Bullock%2C+Theodore++(2000)+Revisiting+the+Concept+of+Identifiable+Neurons.++%5BJournal+(Paginated)%5D+++++&rft.relation=http%3A%2F%2Fcogprints.org%2F1089%2F