Table III.
Autoradiographic distribution of 5‐HT binding sites in the human brain
| Brain region | n | [3H]Citalopram | [3H]WAY‐100635 | [3H]GR 125743 | [3H]M100907 | [125I]SB 207710 | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Mean | SD | Mean | SD | Mean | SD | Mean | SD | Mean | SD | ||
| Limbic cortices | |||||||||||
| Hippocampus CA1–2, pyramidal layer | 7 (5) | 2.6 | 1.7 | 123 | 21 | 3.7 | 2.5 | 27 | 10 | 0.32 | 0.11 |
| CA1–2, molecular layer | 7 (5) | 8.4 | 3.9 | 85 | 19 | 13 | 5.4 | 24 | 7.3 | 0.23 | 0.098 |
| Dentate gyrus | 6 (4) | 6.8 | 3.4 | 52 | 12 | 3.9 | 2.6 | 8.1 | 3.2 | 0.19 | 0.073 |
| Posterior uncus | 2 (2) | 31 | (22, 39) | 108 | (92, 124) | 10 | (9.7, 11) | 13 | (9.1, 17) | 0.19 | (0.15, 0.22) |
| Amygdala (basolateral complex) | 3 (3) | 11 | 4.3 | 13 | 5.5 | 12 | 2.1 | 37 | 3.2 | 0.19 | 0.084 |
| Anterior cingulate gyrus | |||||||||||
| External layers | 7 (4) | 20 | 2.8 | 71 | 3.0 | 19a | 4.4 | 55 | 8.0 | 0.19 | 0.055 |
| Internal layers | 7 (4) | 10 | 2.3 | 19 | 2.8 | 18a | 3.6 | 25 | 3.9 | 0.16 | 0.039 |
| Posterior cingulate gyrus | |||||||||||
| External layers | 2 (2) | 8.7 | (7.7, 9.8) | 43 | (36, 50) | 16 | (15, 16) | 55 | (51, 59) | 0.18 | (0.13, 0.22) |
| Internal layers | 2 (2) | 4.1 | (0.0, 8.2) | 11 | (10, 11) | 9.9 | (9.4, 10) | 24 | (24, 24) | 0.14 | (0.12, 0.16) |
| Subcallosal area | |||||||||||
| External layers | 3 (3) | 43 | 17 | 90 | 9.7 | 15a | (11, 20) | 55 | 11 | 0.13 | 0.017 |
| Internal layers | 3 (3) | 26 | 14 | 31 | 6.1 | 15a | (12, 19) | 27 | 6.9 | 0.14 | 0. 0086 |
| Entorhinal cortex | |||||||||||
| Anterior, external layers | 3 (3) | 36 | 3.1 | 73 | 15 | 19 | 4.3 | 24 | 6.4 | 0.26 | 0.090 |
| Anterior, internal layers | 3 (3) | 13 | 2.6 | 73 | 21 | 13 | 4.4 | 24 | 0.88 | 0.26 | 0.089 |
| Middle, external layers | 3 (3) | 18 | 6.3 | 66 | 18 | 19 | 5.9 | 23 | 2.2 | 0.18 | 0.059 |
| Middle, internal layers | 3 (3) | 7.3 | 0.74 | 38 | 17 | 10 | 6.4 | 21 | 3.3 | 0.22 | 0.065 |
| Posterior, external layers | 3 (3) | 15 | 2.0 | 88 | 21 | 11 | 2.2 | 57 | 14 | 0.22 | 0.10 |
| Posterior, internal layers | 3 (3) | 7.9 | 1.4 | 27 | 8.2 | 11 | 3.5 | 36 | 8.6 | 0.18 | 0.084 |
| Insular cortex | |||||||||||
| External layers | 7 (4) | 12 | 3.2 | 73 | 6.7 | 18 | 3.0 | 60 | 7.4 | 0.18 | 0.043 |
| Middle layers | 7 (4) | 7.8 | 3.3 | 14 | 4.2 | 19 | 3.1 | 61 | 9.0 | 0.12 | 0.045 |
| Internal layers | 7 (4) | 5.3 | 1.9 | 18 | 4.2 | 16 | 3.9 | 30 | 4.5 | 0.12 | 0.024 |
| Temporal polar cortex | |||||||||||
| External layers | 3 (3) | 17 | 4.6 | 97 | 25 | 16 | 1.7 | 67 | 11 | 0.31 | 0.15 |
| Internal layers | 3 (3) | 8.1 | 2.0 | 23 | 3.9 | 17 | 1.5 | 36 | 12 | 0.24 | 0.11 |
| Isocortex | |||||||||||
| Frontal cortex | |||||||||||
| External layers | 7 (4) | 5.4 | 2.2 | 54 | 8.0 | 20 | 2.6 | 56 | 13 | 0.18 | 0.066 |
| Middle layers | 7 (4) | 4.1 | 1.4 | 9.3 | 2.2 | 20 | 2.6 | 59 | 13 | 0.11 | 0.037 |
| Internal layers | 7 (4) | 3.4 | 1.4 | 11 | 1.6 | 16 | 2.7 | 30 | 4.6 | 0.12 | 0.031 |
| Temporal cortex | |||||||||||
| External layers | 6 (5) | 5.2 | 3.3 | 68 | 15 | 14 | 3.2 | 62 | 7.8 | 0.26 | 0.095 |
| Middle layers | 6 (5) | 3.3 | 2.1 | 9.6 | 1.0 | 14 | 3.3 | 60 | 10 | 0.14 | 0.069 |
| Internal layers | 6 (5) | 1.8 | 1.5 | 12 | 3.1 | 11 | 2.7 | 35 | 6.3 | 0.18 | 0.061 |
| Occipital cortex (BA17) | |||||||||||
| External layers | 4 (3) | 3.2 | 2.1 | 23 | 5.1 | 21 | 3.0 | 56 | 13 | 0.12 | 0.027 |
| Middle layers | 4 (3) | 4.4 | 3.8 | 3.0 | 0.60 | 34 | 3.7 | 55 | 9.2 | 0.039 | 0.015 |
| Internal layers | 4 (3) | 4.0 | 3.4 | 1.5 | 0.69 | 16 | 4.0 | 32 | 1.8 | 0.051 | 0.029 |
| Striatum and pallidum | |||||||||||
| Caudate nucleus | 4 (4) | 17 | 4.2 | 1.8 | 1.2 | 16 | 3.8 | 13 | 3.2 | 0.29 | 0.049 |
| Putamen | 4 (4) | 9.8 | 2.6 | 1.1 | 0.70 | 8.9 | 3.4 | 5.4 | 2.5 | 0.24 | 0.021 |
| Ventral striatum | 3 (3) | 19 | 3.6 | 2.8 | 2.0 | 35 | 8.7 | 16 | 3.0 | 0.26 | 0.029 |
| Globus pallidus | 3 (2) | 4.0 | 1.4 | <1 | — | 35 | 1.2 | 1.5 | 2.0 | 0.27 | 0.050 |
| Ventral pallidum | 2 (2) | 15 | (15, 15) | 1.3 | (0.37, 2.2) | 82 | (78, 86) | 3.5 | (2.9, 4.1) | 0.33 | (0.30, 0.36) |
| Thalamus | |||||||||||
| Anterior | 4 (4) | 9.2 | 2.4 | <1 | — | <1 | — | 6.2 | 1.8 | 0.10 | 0.034 |
| Mediodorsal | 4 (4) | 10 | 3.1 | 2.5 | 0.42 | 1.9 | 0.69 | 11 | 1.3 | 0.058 | 0.013 |
| Pulvinar | 4 (4) | 13 | 3.2 | 1.7 | 0.92 | 2.8 | 1.2 | 7.0 | 2.0 | 0.081 | 0.021 |
| Brainstem | |||||||||||
| Substantia nigra | 2 (2) | 9.9 | (7.7, 12) | <1 | — | 38 | (30, 46) | 4.5 | (2.5, 6.5) | 0.30 | (0.29, 0.31) |
| Central gray area | 6 (5) | 56 | 17 | 12 | 6.8 | 27 | 6.0 | 5.6 | 3.4 | 0.11 | 0.039 |
| Dorsal raphe nucleus | 2 (2) | 120 | (108, 132) | 140 | (119, 161) | 21 | (18, 23) | 6.3 | (4.6, 8.0) | 0.14 | (0.13, 0.16) |
Values are presented as specific binding and are expressed in pmol/g tissue, original wet weight; n denotes number of measurements followed by number of subjects in parenthesis. Mean and standard deviation (alternatively the two values where n = 2). For the [3H]100907 binding, data from two brain sections are presented as total binding, as the level of nonspecific binding is very low for this radioligand [Hall et al., 2000]. All other data represent specific binding as obtained by subtraction of nonspecific binding from total binding in anatomically adjacent sections. Data for the frontal and temporal cortices are from the inferior and the middle gyrus, respectively. External, middle, and internal cortical layers roughly correspond to layers I–II, III–IV, and V–VI, respectively for the isocortical regions.
n = 6 and 2 for [3H]GR 125743 binding in the anterior cingulate gyrus and the subcallosal area, respectively (due to tissue destruction in one section).