excitatory glutamatergic input to the dopaminergic system (Mansvelder et al. 2002). In the thalamus, for example, nicotine has direct agonist action on excitatory thalamocortical projection neurons and local circuit neurons, although nicotine also stimulates GABAergic interneurons, so that the relationship between nicotine stimulation and thalamocortical stimulation may be complex (Clarke 2004). There is mixed evidence as to whether or not nicotine stimulates corticothalamic neurons (Clarke 2004).
