Benzodiazepines are a class of drugs that serve as positive allosteric modulators of the GABAA receptor by binding to their own "site" on the aforementioned receptor. By doing this they produce euphoria and a wide range of effects characteristic of Central Nervous System (CNS) depression (e.g. anxiolysis, sedation, amnesia, mental confusion, muscle relaxant effects).
I know that an interaction with the mesolimbic dopamine ("reward") pathway would have to come in somewhere but where? I also know that GABAergic neurons downregulate activity in the mesolimbic dopamine pathway and that this is how opioids and cannabinoids induce euphoria -- they inhibit the release of GABA from presynaptic neurons in the mesolimbic dopamine pathway. I just find that this would be confusing in the case of benzodiazepines since they increase GABA activity, presumably also in the mesolimbic dopamine pathway thus producing dysphoria and not euphoria.
I just would like to know how they manage to induce euphoria in full (what they do to increase activity in the mesolimbic dopamine pathway that thus leads to euphoria)
Please cite journal articles to substantiate your claims.