tokens: Moreover , all adenosine receptor agonists : 2 - p - ( 2 - carboxyethyl ) phenethylamino - 5 ' - N - ethylcarboxamidoadenosine ( CGS 21680 ) , A2A receptor agonist , N6 - cyclopentyladenosine ( CPA ) , A1 receptor agonist , and 5 ' - N - ethylcarboxamidoadenosine ( NECA ) , A2 / A1 receptor agonist significantly and dose - dependently decreased cocaine - induced locomotor activity .