Retrospective descriptive report comparing access systems to refine intravenous self-administration in rats.

For operant self-administration, permanent intravenous cannulas need to remain open and operational for months without infections or blockages. Here, we report retrospectively on our experiences and observations using different access systems during three studies. We identified a refined method for vena jugularis cannulation that is a vast improvement for the animals, biotechnicians and researchers. A closed and membrane-sealed system equipped with a magnet in the backmount was easy to use, allowed quick (dis)connection, caused no more than 10% of the animals a little irritation and superficial infection (softer patch), prevented clogging (closed system) and allowed for social housing (metal cap).