Animal models of anxiety

• 1.

  1. A theory of anxiety and the psychological action of anti-anxiety drugs is presented, based (a) on a general theory of learning which postulates that emotional behaviour is the outcome of an interaction between two basic learning processes (classical and instrumental conditioning); and (b) on experiments on the behavioural effects of anti-anxiety drugs (benzodiazepines, barbiturates, alcohol) in animals.

• 2.

  2. The theory proposes that the effective stimuli for anxiety are stimuli associated with punishment, stimuli associated with frustrative non-reward, and novel stimuli; the behavioural consequences of anxiety are an inhibition of ongoing behaviour, increased arousal, and increased attention to novel features of the environment.

• 3.

  3. Physiological experiments suggest that the neural substrate of anxiety thus defined includes the septo-hippocampal system (SHS) and its monoaminergic inputs from the brain stem, especially the dorsal ascending noradrenergic bundle (DANB).

• 4.

  4. The SHS-DANB system is also concerned with aspects of the development of behavioural tolerance for non-reward or punishment; and the anti-anxiety drugs, under certain conditions, block the development of this tolerance.