The present invention relates to a composition for improving cognitive functions, comprising somatostatin or cortistatin as an effective component and, more specifically, to a composition for improving cognitive functions, which activates somatostatin receptors to improve visual perception skills. Also, the present invention relates to a composition for preventing or treating cognitive disorders, comprising somatostatin or cortistatin as an effective component. According to the present invention, somatostatin or cortistatin may be used to directly activate the somatostatin receptors to reduce excitatory synaptic transmission to inhibitory neurons expressing parvalbumin genes and to improve selective reactivity to visual information within a cortical circuit. Also, the somatostatin of the present invention and its biological peptide analogue can maintain their structures stably, and unlike artificially produced peptides, show non toxicity, and thus can be safely implanted in a living body. Also, the present invention may find a direct application in the restoration of cognitive functions through inducing the activation of somatostatin receptors by implanting somatostatin or its neuropeptide analogue directly into the brain or cerebrospinal fluid of a patient with damaged brain cognitive functions. Furthermore, the present invention may be beneficially used in the development and in vivo applications of biological peptide analogue compounds and artificial peptide compounds for the purpose of improving signal transduction through the activation of somatostatin receptors in cortical neurons.
Enhancement or Impairment of Cognitive Brain Function via Regulation of the Somatostatin Receptors in the Brain