Do you know an authoritative source for the approximate number of dopaminergc cells in the ventral tegmental area (VTA)? Ideally I would like to know this for mice, rats, as well as humans, but one species alone would be a nice start. I have looked for this via google scholar and pubmed, but found nothing.
Approximately, 250000-440000 neurons in Humans (Rice et al., 2016).
The substantia nigra/ventral tegmental area (SN/VTA) complex is a heterogeneous collection of dopaminergic cell groups that extends from diencephalic to mesencephalic territories in many vertebrates, including rodents, non-human primates, and humans (Puelles and Verney 1998; see as reviews Smits et al. 2006; Smidt and Burbach 2007; Smits et al. 2013). The SN/VTA contains the largest number of dopaminergic neurons in the brain (see as reviews van Domburg and ten Donkelaar 1991; Haber and Fudge 1997; Nieuwenhuys et al. 2008), with average estimates ranging in most studies from approximately 250,000 – 440,000 dopaminergic neurons within the complex (Bogerts et al. 1983; Hirsch et al. 1988; van Domburg and ten Donkelaar 1991; Damier et al. 1999a; Kubis et al. 2000).