The root NeuroML Level 3 element. Description of neuronal models, including biophysics and channel mechanisms, and network connections (NeuroML Level 3). Unit of all length measurements. Usually has the value <b>micrometer</b>. Note: length_units will be the preferred form in v2.0 Unit of all length measurements. Usually has the value <b>micrometer</b>. Note: length_units will be the preferred form in v2.0 Unit of all volume measurements. Set of Level 3 cells A single cell specified in MorphML extended to include channel density info. Cell with extensions for biophysics, and network functionality Note: from v1.7.1 the preferred way to specify a potential synaptic location is with a potential_syn_loc element under connectivity under cell, as opposed to the potentialSynapticLocation under biophysics under cell. The former will be the only option from v2.0 Biophysics of Level3 cell, including specification for allowable synaptic locations. Note: from v1.7.1 the preferred way to specify a potential synaptic location is with a potential_syn_loc element under connectivity under cell, as opposed to the potentialSynapticLocation under biophysics under cell. The former will be the only option from v2.0