To classify an aphasia, it is necessary to determine whether the patient can (1) speak fluently, with normal articulation and rhythm and without paraphasic, syntactic or grammatical errors or use…

There are two main types of explicit memory: episodic and semantic memory. Episodic memory is likened to autobiographic memory, as an episode of one’s life is recalled (remembering a certain…

Registration of Information. If information is not registered initially, it will not be remembered later. Failure to register is the explanation for absentmindedness, probably the most common abnormality of memory….

Recent years have witnessed a growing appreciation for functional roles astrocytes play within the CNS. It increasingly appears to be the case that astrocytes are integral to brain energy utilization….

Test Language Function. Judge the fluency of the patient’s language. Note whether language is effortful or not, and if there are mistakenly spoken phonemes or mistakes in grammar. Evaluate comprehension…

The principle of summation relates to the fact that a neuron typically has a large number of synaptic terminals (boutons) ending upon it; alone, each bouton is capable of producing…

Interneurons. Interneurons have axons that do not leave the cortex and may be of several kinds. The most common are stellate (star-shaped), or granule, cells, which have symmetrically branching dendritic…

Synaptic transmitter substances are concentrated in synaptic vesicles within the bouton. Although the exact mechanism of its release is unknown, it appears that the transmitter substance is released in packets,…

The highly branched dendritic tree has a much greater surface area than the remainder of the neuron and is the receptive part of the cell. Incoming synaptic terminals make contact…

Behavioral changes produced by cortical ablations, such as prefrontal lobotomy, are well known. Other such changes, varying from mania and hyperphagia to apathy, aphagia, and somnolence, result from lesions to…