diameter just under 0.5mm: height 1.2mm: number of neurons ~15,000: number of synapses 10^8
||Smith, S.J (2007) Circuit Reconstruction Tools Today. Curr. Opin. In Neurobiol. 17: 601-608. p.606 right column 2nd paragraphPubMed ID18082394
|| T.A. Woolsey, M.L. Dierker, D.F. Wann Mouse SmI cortex: qualitative and quantitative classification of golgi-impregnated barrel neurons Proc Natl Acad Sci U S A, 72 (1975), pp. 2165–2169  D. Kleinfeld, E. Ahissar, M.E. Diamond Active sensation: insights from the rodent vibrissa sensorimotor system Curr Opin Neurobiol, 16 (2006), pp. 435–444PubMed ID1056021, 16837190
||p.606 right column 2nd paragraph:"The whisker barrel is a patch of rodent sensorimotor cortex that processes information associated with one contralateral whisker (vibrissa), and is one element of a closely packed somatotopic array of barrels, one per whisker [primary sources]. Each barrel occupies a columnar volume just under 0.5 mm in diameter and 1.2 mm tall, and includes approximately 15,000 neurons and 100 million synapses. Although a whisker barrel in isolation, bereft of its extrinsic cortical and subcortical connections, is not a functionally complete circuit, it is arguably the most widely recognized and agreed upon example of an anatomically distinct cortical circuit module."