Day differences in the cortisol awakening response predict day differences in synaptic plasticity in the brain

Figures & data

Table 1. Descriptives of MEP-ratios (mean of 0, 5, 10, 20 and 30 min after rTMS relative to base) cortisol concentrations (nmols/l) from 0- to 45-min post-awakening, CAR mean increase (MnInc) and awakening time.

Measure	Mean	SD
Average MEP ratio	0.90	0.29
Cortisol 1 (0 min)	14.63	9.73
Cortisol 2 (15 min)	16.37	7.06
Cortisol 3 (30 min)	18.06	7.75
Cortisol 4 (45 min)	17.14	7.43
CAR (MnInc)	2.72	9.29
Awakening time (hh:mm) am	7.49	1.25

Table 2. F-ratios, df and significances associated with parameters in mixed regression modelling of MEP ratio data.

Model parameter	df (num,denom)	F	p
Intercept	8.14	158.83	0.000
Sample number (1–5)	149.72	1.61	0.189
Session number (1–4)	148.17	0.56	0.689
CAR (within participants)	148.24	10.41	0.002

Figure 1. Relationship between morning CAR and afternoon mean rTMS response. Data are expressed relative to individuals’ own mean of study CAR or MEP ratio over the 4 days of sampling (i.e. zero on each axis). Because the rTMS effect is inhibitory, a small mean MEP ratio indicates a large rTMS response. The polarity of the y axis in this figure is accordingly reversed so that a more positive value indicates greater neuroplasticity.