The construction that places two nouns after a verb, as in the sentence “John gave Bill the ball”. Verbs such as ‘give’ can appear in both the double object dative construction as in this example, and also in the prepositional dative construction as in “John gave the ball to Bill’”. There is a class of …
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Dorsolateral prefrontal cortex (DLPFC)
One of the three main sub-divisions of the frontal cortex (see figure below) encompassing Brodmann’s areas 9-12, 47 and 48, with afferences from areas 7, 10 and 46 as well as from the dorsal thalamus, the parafasicular area of the thalamus, substantial nigra, medial pars compacta, dorsal raphe and the periacueductal (‘central’) gray substance. This …
Dorsal roots
Also called the posterior roots because they are the more posterior of the two nerve fiber bundles (the other being the ventral root), the dorsal roots are formed by afferent axons, whose neurons are contained in the dorsal root ganglia located in the intervertebral foramen. They consist of sensory fibers derived from the skin as …
Dorsal visual pathway (or stream)
A cortical visual processing pathway that runs caudal to rostral from the occipital lobes in the primary visual cortex to dorsal temporal cortex and parietal lobes, and processes information relative to recognizing the spatial locations of whole objects as well as serving to visually guide on-line actions related to objects that are made in the …
Dorsal rhizotomy
In this irreversible surgical procedure, selected dorsal (sensory) nerve roots in the spinal cord are cut to prevent them from stimulating the spastic muscles (see figure below), hence it is also termed selective dorsal rhizotomy. Usually administered when a child with cerebral palsy is between 2 and 6 years of age, it may permanently reduce …
Dorsal root ganglia (DRG)
Location of unipolar primary sensory neurons contained in nodules or swellings, lying lateral and dorsal to the dorsal roots the spinal cord. Looking like a golf ball on a tee, they have concentrically located nuclei (see figure below). In sensory ganglia, there are no synaptic contacts between neurons. Dorsal roots: sensory axons (blue) pass …
Dorsal plate in limb bud
A plate-like concentration of (dorsally located) mesenchmal cells in the extremities, giving rise to flexor muscles. A limb bud is an outgrowth and projection of tissue that forms future limbs. See Dorsal, Embryo, Limb bud, Mesenchyme, Ventral plate in limb bud
Dorsal commissural interneurons
Interneurons of the spinal cord that cross the ventral midline. During development, these interneurons are attracted along a gradient of netrin so that they grow directly to and terminate at the ventral midline of the spinal cord, netrin being relased by the floor plate ( a specialized glial structure). . See Anterior commissure, …
Dorsal horn
H-shaped tray matter column (see figure below) at dorsal side of the spinal cord (i.e., situated toward the spine) and one of two major routes by which afferent information (i.e., somaesthesis) is carried to the thalamus via the dorsal roots (the other being the spinothalamic tract that transmits information about pain and temperature). Bilateral transection …
Dorsal
From the Latin word meaning ‘to the back’, it is facing away from the main of axis of an organ or organism. Thus, it can designate, for example, the surface of an animal directed away from the substrate or the dorsal column of the spinal cord. In the human forebrain, however, ‘dorsal’ can mean the …