Learning by neurones: role of attention, reinforcement and behaviour.

The importance of the behavioural situation, attentional demands of the task, and stimulus-reinforcement contingencies in promoting or permitting experience-dependent neuronal plasticity is argued. Evidence is provided for the specific activation of the locus coeruleus noradrenergic system of the rat by novel stimuli encountered while investigating the environment, as well as during a formal learning situation. Noradrenergic neurons are particularly concerned with changes in the predictive value of the stimulus, when new learning should occur. Noradrenaline, released at LC terminals in target sensory systems, could facilitate shifts in attention, information processing and memory through its well-documented gating and tuning effects and its permissive role in long-term potentiation. Dopamine neurons, which fire persistently to reward during learning, could be involved in maintaining the behavioural response.

[1]  W. Singer,et al.  Different voltage-dependent thresholds for inducing long-term depression and long-term potentiation in slices of rat visual cortex , 1990, Nature.

[2]  J. Sarvey,et al.  Norepinephrine induces pathway-specific long-lasting potentiation and depression in the hippocampal dentate gyrus. , 1989, Proceedings of the National Academy of Sciences of the United States of America.

[3]  J. Konorski.  Integrative activity of the brain , 1967 .

[4]  J. Sarvey,et al.  Norepinephrine regulates long-term potentiation of both the population spike and dendritic EPSP in hippocampal dentate gyrus , 1987, Brain Research Bulletin.

[5]  F. Gage,et al.  Absence of long-term potentiation in the subcortically deafferented dentate gyrus , 1989, Brain Research.

[6]  S. Sara,et al.  Response to Novelty and its Rapid Habituation in Locus Coeruleus Neurons of the Freely Exploring Rat , 1995, The European journal of neuroscience.

[7]  T. Sejnowski,et al.  The predictive brain: temporal coincidence and temporal order in synaptic learning mechanisms. , 1994, Learning & memory.

[8]  C. Harley,et al.  Novelty‐elicited, Noradrenaline‐dependent Enhancement of Excitability in the Dentate Gyrus , 1997, The European journal of neuroscience.

[9]  Donald J. Woodward,et al.  Modulation of rat cortical area 17 neuronal responses to moving visual stimuli during norepinephrine and serotonin microiontophoresis , 1990, Brain Research.

[10]  M. Segal,et al.  Plasticity of sensory responses of locus coeruleus neurons in the behaving rat: implications for cognition. , 1991, Progress in brain research.

[11]  C. Harley,et al.  Long-lasting potentiation of the dentate gyrus population spike by norepinephrine , 1983, Brain Research.

[12]  S. Sara,et al.  Enhancement of excitability and inhibitory processes in hippocampal dentate gyrus by noradrenaline: A pharmacological study in awake, freely moving rats , 1991, Neuroscience Letters.

[13]  R. Rescorla,et al.  A theory of Pavlovian conditioning : Variations in the effectiveness of reinforcement and nonreinforcement , 1972 .

[14]  Peter Dayan,et al.  A Neural Substrate of Prediction and Reward , 1997, Science.

[15]  M. Segal,et al.  An α2 antagonist, idazoxan, enhances EPSP-spike coupling in the rat dentate gyrus , 1991, Brain Research.

[16]  K Sakai,et al.  Neuronal tuning and associative mechanisms in form representation. , 1994, Learning & memory.

[17]  Y. Frégnac,et al.  A cellular analogue of visual cortical plasticity , 1988, Nature.

[18]  M. Ahissar,et al.  Dependence of cortical plasticity on correlated activity of single neurons and on behavioral context. , 1992, Science.

[19]  S. Sara,et al.  Locus coeruleus-evoked responses in behaving rats: A clue to the role of noradrenaline in memory , 1994, Brain Research Bulletin.

[20]  G. Aghajanian,et al.  Modulation of lateral geniculate neurone excitability by noradrenaline microiontophoresis or locus coeruleus stimulation , 1980, Nature.

[21]  D C Van Essen,et al.  Information processing in the primate visual system: an integrated systems perspective. , 1992, Science.