Distribution of spiny neurons in the <i>Xenopus</i> tadpole brain.

<p>Fluorescent dye was electroporated into neurons located in different brain regions. (A1, A2) Spiny neuron in the OB. (A1) Electrode filled with fluorescent dye inserted into the OB, pointing to a labeled neuron. (A2) High magnification of the neuron in A1. Inset shows spines on a dendrite. (B1, B2) Mitral cell in the anterior OB. (C1, C2) Spiny neuron in the telencephalon (Tel). (D1, D2) Non-spiny neuron in the tectum (Tec). (E) Diagram summarizing all labeled spiny (red) and non-spiny (blue) neurons in different brain areas in the left hemisphere. Twenty neurons randomly labeled in the optic tectum were non-spiny neurons; 69 neurons in the OB and telencephalon were spiny neurons except for 11 neurons.