A hypothesis on the functional significance of the dendritic projections of spinothalamic tract cells to the white matter of the cat spinal cord.
Deep, lumbar, spinothalamic tract cells have fine distal dendrites which project to, and receive synaptic connections within, the ventral (VF) and/or lateral funiculi (LF). The projection to the LF is inversely related (P less than 0.05) to the projection of the VF. It is proposed that the white matter dendrites receive a particular level of tonic, excitatory drive from a wide variety of axons in the VF and/or LF and that this drive is responsible for the spontaneous activity seen in these cells; activity which provides a baseline against which particular forms of natural stimulation may be registered either by causing an increase or a decrease in the firing frequency.
D000818:Animals; D002415:Cats; D003712:Dendrites / Q000502:physiology* / Q000648:ultrastructure; D005071:Evoked Potentials; D009474:Neurons / Q000502:physiology / Q000648:ultrastructure; D013116:Spinal Cord / Q000033:anatomy & histology / Q000502:physiology*; D013133:Spinothalamic Tracts / Q000033:anatomy & histology / Q000502:physiology*; D013569:Synapses / Q000502:physiology; D009435:Synaptic Transmission