Ratbot navigation using deep brain stimulation in ventral posteromedial nucleus

Figures & data

Figure 1. Bipolar-twisted electrodes. Two extra pins were considered in order to prevent the electrode and the ground wire pins to get damaged by the rats.

Figure 2. A rat at the final surgery stage. Two VPM electrodes are placed in the head.

Figure 3. A histology image example (placement confirmation of the left side electrodes).

Table 1. The Stimulation Parameters of the First Ratbot.

	Day 1^a	Day 9^b	Day 42^c	Day 46	Day 47	Day 49	Day 50^d	Average
Left electrodes impedance (kΩ)	66 & 76	83 & 87	52 & 66	68 & 80	62 & 72	84 & 91	93 & 97	73 & 81
Right electrodes impedance (kΩ)	38 & 40	45 & 72	31 & 50	19 & 26	43 & 58	47 & 66	69 & 73	42 & 55
Left side number of pulses	-	100	50	25	25	25	25	42
Right side number of pulses	-	200	100	70	50	20	20	77
Left side Amplitude (µA)	-	100	100	100	100	100	100	100
Right side amplitude (µA)	-	100	100	200	200	200	150	158
Left side pulse width (ms)	-	200	100	200	200	200	100	167
Right side pulse width (ms)	-	200	300	500	300	250	200	292
Left side interphase (ms)	-	120	120	120	120	120	120	120
Right side interphase (ms)	-	120	120	120	120	120	120	120
Left side frequency (Hz)	-	100	100	100	100	100	100	100
Right side frequency (Hz)	-	100	100	100	100	100	100	100

The Stimulation Parameters were obtained each day according to the instructions explained in Section 2.4.. We changed the parameters every session to obtain the suitable rotational behavior. ^aSurgery date; ^bafter at least a week of recovery; ^cfirst training session; ^dlast test session.

Table 2. The Stimulation Parameters of the Second Ratbot.

	Day 1^a	Day 7	Day 10^b	Day 31^c	Day 32	Day 33	Day 34^d	Average
Left Electrodes Impedance (kΩ)	72 & 81	90 & 94	168 & 173	79 & 80	48 & 65	80 & 83	70 & 77	87 & 93
Right Electrodes Impedance (kΩ)	75 & 84	97 & 106	95 & 169	68 & 80	83 & 93	73 & 79	72 & 80	80 & 99
Left side number of pulses	-	100	100	70	70	70	70	80
Right side number of pulses	-	200	200	50	70	70	70	110
Left Side Amplitude (µA)	-	200	200	100	100	100	100	133
Right Side Amplitude (µA)	-	150	150	200	200	200	200	183
Left Side Pulse Width (ms)	-	200	200	100	200	100	100	150
Right Side Pulse Width (ms)	-	300	300	400	300	300	300	317
Left side Interphase (ms)	-	120	120	100	100	100	100	107
Right side Interphase (ms)	-	100	100	100	100	100	100	100
Left Side Frequency (Hz)	-	100	100	100	100	100	100	100
Right Side Frequency (Hz)	-	150	150	100	100	100	100	117

The Stimulation Parameters were obtained each day according to the instructions explained in Section 2.4. We changed the parameters every session to obtain the suitable rotational behavior. ^aSurgery date; ^bafter at least a week of recovery; ^cfirst training session; ^dlast test session.

Figure 4. Impedance Changes over Time for the Left Electrodes of the First Ratbot.

Table 3. The Navigation Performance of the First Ratbot.

	Test Session
	#1	#2	#3
Correct Rotations	13	25	10
Incorrect Rotations	1	0	1
Performance (%)	93	100	91
Total Performance (%)	96

Table 4. The Navigation Performance of the Second Ratbot.

	Test Session
	#1	#2	#3
Correct Rotations	13	14	16
Incorrect Rotations	3	1	3
Performance (%)	81	93	84
Total Performance (%)	86

Figure 5. Impedance Changes over Time for the Right Electrodes of the First Ratbot.

Figure 6. Impedance Changes over Time for the Left Electrodes of the Second Ratbot.

Figure 7. Impedance Changes over Time for the Right Electrodes of the Second Ratbot.