Attention prefrontal cortex

The frontal cortex consists of three main structures (i) motoric regions (including the Broca area and ocular areas), (ii) the prefrontal cortex, and (iii) the orbital cortex. The prefrontal cortex is associated with attention, arousal, and expectation, the orbital cortex with motivation. 

The prefrontal cortex (PFQ and in particular the dorsal lateral part (DLPFQ appear to be particularly important in schizophrenia (Kerwin 1992). Lesions there are known to produce functional defects in humans reminiscent of many of the negative symptoms of schizophrenia, such as attention and cognitive defects and withdrawal. Despite this, no specific pathology is seen in the DLPFC in schizophrenics although there is some atrophy and neuronal loss which are normally old and could be congenital. That being so, it is necessary to explain why the symptoms become apparent only in adolescence. 

Kane M, Engle R. 2002. The role of prefrontal cortex in working-memory capacity, executive attention, and general fluid intelligence an individual-differences perspective. Psychon Bull Rev 9(4) 637-671. 

Lambe EK, Picciotto MR, Aghajanian GK (2003) Nicotine induces glutamate release from thalamocortical terminals in prefrontal cortex. Neuropsychopharmacology 28 216-225 Lanca AJ, Adamson KL, Coen KM, Chow BE, Corrigall WA (2000) The pedunculopontine tegmental nucleus and the role of cholinergic neurons in nicotine self-administration in the rat a correlative neuroanatomical and behavioral study. Neuroscience 96 735-742 Lawrence NS, Ross TJ, Stein EA (2002) Cognitive mechanisms of nicotine on visual attention. Neuron 36 539-548... 

Rodent models thus provide opportunities to explore the relationship between dopaminergic function, attention and consciousness. Based upon the well designed study of Granon et al. (2000) showing a clear improvement of attentional performance after the infusion of a D1 agonist into the prefrontal cortex, further study of cortical arousal and variability of reaction times in these models may provide important information. The preliminary data indicating that D2 receptor antagonists may increase cortical arousal (Sebban et al., 1999) is contrary to expectation and requires confirmation... 

Improve Inhibitory control of behavior and attention in both the cognitive and affective realms by optimizing neurochemical influences in prefrontal cortex via alpha-2A noradrenergic receptors (stimulants,... 

Godefroy, O. and Rousseaux, M. (1996) Divided and focused attention in patients with lesion of the prefrontal cortex. Brain Cogn 30 155-174. 

Studies of animals with central cholinergic lesions produced by either pharmacological inhibition of choline uptake or direct excitotoxic lesions of basal forebrain cholinergic neurons have shown highly specific attentional deficits (Muir et al. 1992 Robbins et al. 1989). These animals showed deficits that might be predicted from studies of humans with AD that is, they showed increased response latency and increased responsiveness to irrelevant sensory stimuli. Studies by Vidal (1994b) have shown that administration of a nicotinic antagonist into rat prefrontal cortex impairs performance on spatial... 

Bymaster FP, Katner JS, Nelson DL, et al Atomoxetine increases extracellular levels of norepinephrine and dopamine in prefrontal cortex of rat a potential mechanism for efficacy in attention-deficit/hyperactivity disorder. Neuropsychopharmacology 27 699-711, 2002... 

Attention has been focused on dopamine because of its relationship to neurological diseases and to addiction (discussed in Section 10). Dopamine receptors constitute a large family, which are classified into two main subfamilies. The D, subfamily consists of D1a and D1B (D5) receptors and the D2 subfamily of D2, D3, and D4 receptors.763 764 The D, receptors, which are prominent in the prefrontal cortex and also in the striatum, are more abundant than the D2 receptors, which are also present in the striatum and the pituitary and are targets for antipsychotic drugs such as haloperidol (Fig. 30-33).765 The recently discovered and less numerous D3 receptors are present in only a few regions of the brain. However, a deficiency of D3 receptors may also be involved in addiction, schizophrenia, and Parkinson disease.766 767... 

There are many specific noradrenergic pathways in the brain, each mediating a different physiological function. For example, one projection from the locus coeruleus to frontal cortex is thought to be responsible for the regulatory actions of NE on mood (Fig. 5—24) another projection to prefrontal cortex mediates the effects of NE on attention (Fig. 5—25). Different receptors may mediate these differential effects of norepinephrine in frontal cortex, postsynaptic beta 1 receptors for mood (Fig. 5—24) and postsynaptic alpha 2 for attention and cognition (Fig. 5—25). 

Prefrontal cortex Pi a2 Excitation of pyramidal neurons. Inhibition of GABA basket cells General activity, cognition, behavior flexibility, attention, concentration... 

Granon S, Passetti F, Thomas KL, Dailey JW, Everitt BJ, Robbins TW. Enhanced and impaired attentional performance after infusion of D1 dopaminergic receptor agents into rat prefrontal cortex. J Neurosci 2000 20 1208-1215. 

Birrell JM, Brown VJ. Medial prefrontal cortex mediates perceptual attentional set shifting in the rat. J Neurosci 2000 20 4320-4324. 

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